So perhaps Lo'ihi is due for some more truly eruptive activity.
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They have an eruptive sardonic energy; devotion mixes with a sharply humorous misanthropic edge.
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Eruptive activity includes elevated seismic actions, lava flows and plumes of steam and ash.
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Painting surfaces are punched or slashed through, or ooze as if with eruptive disease.
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Lava viewing cruises are appealing to tourists visiting the Big Island, Hawaii's only eruptive island.
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"This deal ... is a factor of peace and stabilization in a very eruptive region," Parly said.
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Three other fissures were also producing some eruptive action Monday night, while the others were quiet.
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Our solar system is rife with geologic activity, from eruptive ice moons to mountainous dwarf planets.
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Mount Rainier is an active volcano, but its last eruptive period was about 1,000 years ago, CNN reported.
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Europa isn't only the eruptive moon that might be sheltering warm, life-friendly waters beneath its frozen exterior.
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The former definitely involved plenty of eruptive material, whose huge pumice raft was first spotted from a plane.
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They compared the predictions of their model to the known eruptive behavior of vents across Italy's Campi Fleigrei,
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Kanlaon produced a few small explosions last November and December but hasn't had a major eruptive period since 2006.
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"The long-running eruptive activity that began in 1983 appears to have ended," Neal said in a phone interview.
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"It's unbelievably eruptive in terms of its population," said Michael Saunders, a professor emeritus of entomology at Penn State.
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The world is an eruptive flux of frequently toxic emergent behavior, and every unexpected event is laced with subtle interconnected nuances.
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Though its last eruptive period was about 1,000 years ago, Rainier is an active volcano, so it is inherently unstable, Bacher said.
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"Several additional eruptive fissures or vents — each several hundred yards long — have opened over the past day," said the Hawaiian Volcano Observatory.
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They also point out that emergency planners are constantly on the lookout for much smaller signs of eruptive activity at the volcano.
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Fortunately the eruptive activity of Kilauea has "paused," with no new lava flows since August 9, according to the Hawaiian Volcano Observatory.
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"Volcanoes show precursory signs of eruptive activity — what we call 'unrest,'" a spokesperson for the US Geological Survey said in an email.
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They have asked citizens to get no closer than 12 km from the volcano, which began a new eruptive stage in 1994.
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"Such intense seismic activity probably signifies continuous magmatic intrusion beneath the Taal edifice, which may lead to further eruptive activity," Phivolcs said.
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"This deal ... is a factor of peace and stabilisation in a very eruptive region," French Defence Minister Florence Parly told RTL radio.
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Fortunately, the eruptive activity of Kilauea has "paused," with no new lava flows since August 9, according to the Hawaiian Volcano Observatory.
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"At this time eruptive activity is increasing and is expected to continue," the County of Hawaii's Civil Defense Agency reported late Saturday.
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Bennett warned that an eruptive Mount Paektu, which is bisected by the China-North Korea border, could kill tens of thousands of people.
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He cupped his ear to an eruptive Wells Fargo Center crowd, à la Allen Iverson, the little giant who once flamboyantly roamed this arena.
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Shishaldin has been in an on-and-off eruptive phase since July, occasionally dribbling lava down its snowy flanks and puffing ash and steam.
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Geologists with the USGS say this is a sign that magma is continuing to enter the rift zone and that additional eruptive activity is likely.
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" Yellow is the second level on the Hawaii Volcano Observatory's color-coded alert chart, above green, which is used to indicate "background, non-eruptive state.
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"But White Island Tours does warn that "passengers should be aware that there is always a risk of eruptive activity regardless of the alert level.
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Baby suns, it turns out, are extremely eruptive, releasing mind-boggling amounts of energy during "solar superflares" that make our wildest space weather look like drizzle.
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Adam Driver received his first Tony Award nomination this week for his performance as Pale, the eruptive, coked-up restaurant manager in "Burn This" on Broadway.
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He is just 24, but he was at the core of Dada, the previous decade's most eruptive cultural phenomenon — and he is in the mood for publicity.
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"They're mostly random and experience phases of alternating eruptive activity," Michael Poland, the USGS scientist-in-charge of the Yellowstone Volcano Observatory, wrote in an email to CNN.
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When it is in an eruptive period, the volcano can regularly throw volcanic bombs and ash multiple kilometers from the active vent—this eruption was doing just that.
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He is tenderer and less eruptive than Peter Saul, but his message is just as urgent, disquieting, and necessary to these addled, disjointed, the rich-get-richer times.
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"Because the lava intrusion is still active and earthquakes are still occurring, we still think there's a decent chance of new eruptive activity at the surface," Steven Brantley said.
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As always, there will be plenty for children to see and do: circus arts, robot combat, street dance battles and the eruptive fun of combining Coke Zero and Mentos mints.
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That deluge of data from both professional astronomers and amateurs might one day help scientists with forecasting eruptive solar ejections, or "space weather," detrimental to communication satellites and power grids.
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When volcanoes stop erupting magma for that long, the next eruption generally will happen in a different spot, marking a new eruptive event, said Tina Neal, the observatory's scientist in charge.
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"In this case, we can see how certain symbology can be eruptive and damaging for a democracy when used in political causes," said Aleksandar Petrov, an architect and author in Skopje.
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His eruptive dunks and movements captivated a nightly audience even then, including President Barack Obama who made a special visit to witness Williamson in person during a February 2019 college game.
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Friday also saw several more eruptive lava fissures, each several hundred yards long, in the Leilani Estates subdivision in the Puna District about a dozen miles (19 km) from the volcano.
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And and those words are an apt description of the stirring work, which runs some 23 minutes, tracing a symmetrical arc, from quiet, through frenetic and eruptive activity, back to quiet.
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From her first song, "Madrugada sem Sono" ("Dawn Without Sleep"), Ms. João summoned a full spectrum of fado's tempestuous passions, from hushed melancholy to eruptive, rough-edged, tearful peaks to aching resignation.
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Satellite observations showed no evidence of further "eruptive activity" on Mount Pavlof and low levels of seismic activity suggested that the volcano had subsided, the Alaska Volcano Observatory said in a statement.
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The day also saw several more eruptive lava fissures, each several hundred yards long, in the Leilani Estates subdivision in the Puna District about a dozen miles (261 km) from the volcano.
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Mount St. Helens is one of the most active volcanoes of the Cascade Arc, a string of eruptive mountains that runs parallel to the Cascadia subduction zone from northern California to British Columbia.
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"Before going supernova, the star experiences very significant instabilities in its interior, affecting the outer envelopes and surface, which causes this elevated, maybe even eruptive, mass loss, just before the explosion," Yaron said.
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And the shift of emotional magma beneath the surface seems to have had an eruptive impact on Johns, because from this point forward his work spills out in any number of unexpected directions.
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It has been over 200 years since Hood's last eruption, a period that is referred to as the "Old Maid" eruptive period when a small lava dome was formed just off the volcano's summit.
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The last time the volcano erupted was in 1865 AD. "The volcano has erupted episodically for about 500,000 years and hosted two major eruptive periods during the past 1,500 years," the USGS explained . 5.
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The volcano's aviation alert level was raised to red, or warning level, Sunday morning when data from the Alaska volcano observatory showed that eruptive activity had intensified, according to the United States Geological Survey.
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Only Bartok's angular and eruptive Second Piano Concerto might have posed a bit of a challenge for listeners, and that was mollified by the presence of Yefim Bronfman, one of New York's favorite pianists.
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"Ixcanul" means "volcano" in the Kaqchikel language, and the title refers both to the peak that overlooks the Guatemalan coffee plantation where the film is set and to the eruptive emotions at the movie's core.
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Sunday's eruptive activity created lava flows on the northeast and north flanks of the volcano as well as a steam and ash plume that extended 90 miles east southeast at a height of 20,000 feet.
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Image: Southwest Research InstituteReason number 9,000 not to colonize Jupiter's moon Io: not only is it a frigid hellscape covered in eruptive ice volcanoes and lashed by the gas giant's powerful radiation belts, but the atmosphere just collapsed.
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"Despite the eruptions and harsh climate, this area maintained a diversity of animals, at least during part of the eruptive phase," said Steve Brusatte, a paleontologist at the University of Edinburgh who was not involved in the study.
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The 35-year streak Kilauea's eruptive history spans tens of thousands of years, and the volcano has long inspired fascination and anxiety, as a tourist-drawing pillar of Hawaii Volcanoes National Park and as a force that uprooted lives.
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In his September 8 proclamation, Kim said the United States Geological Survey (USGS) and Hawaii Volcano Observatory (HVO) had lowered the volcanic threat level from red to orange but still could not say when the eruptive event would end.
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A team of astronomers at UC Berkeley has just completed a two and a half year survey of Jupiter's eruptive satellite Io, using the near infrared optical capabilities of the Keck II and Gemini North telescopes at Mauna Kea, Hawaii.
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Although not all volcanoes follow such a steady, pre-eruptive pattern, they typically either tremble, deform or belch volcanic gases — meaning that if scientists monitor these three signals, they will likely be able to forecast when a volcanic eruption will happen.
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Most of the ash production has been relatively minor, but Sunday's event was serious enough to warrant a "code red" warning for air traffic to avoid the area, the second such warning in the volcano's current eruptive phase, Fee said.
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EST: Per the USGS: University of Hawaii at Hilo scientists, who are conducting chemical analysis of the lava, said the olivine they're seeing in eruptive products does not match the crystal size and shape of the ones photographed in the tweet below.
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"What actually happened is that, based on Kilauea Volcano's behavior over the past 8 months and its lack of eruptive activity, the USGS Hawaiian Volcano Observatory lowered the Volcano Alert Level for Kilauea to NORMAL," USGS spokeswoman Janet Babb said in an email.
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Popular imagery of volcanoes may imply that these crowning caldrons of liquid fire are common, but there were thought to be only seven contemporary volcanoes on Earth with persistent lava lakes that have been seen to stick around beyond a single eruptive outburst.
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Her compositions are drafted in an original language, full of rattling counterpoint and eruptive flair, and she inspires fantastic work from every member of her octet — especially the brilliant pedal steel guitarist Susan Alcorn, whose chiming sustain contrasts neatly with her own pluck and decay.
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"The age and appearance of the material surrounding the bright dome indicate that Cerealia Facula was formed by a recurring, eruptive process, which also hurled material into more outward regions of the central pit," Nathues, NASA Dawn's framing camera lead investigator, said in a press release.
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"You're going to either get in there ahead of time and put in the instrumentation you need, or you're just going to accept that you're going to go blind into the entire eruptive period and whatever happens, happens," said Jacob Lowenstern, a geologist with the United States Geological Survey.
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Four wall-sized paintings serve as the exhibition's pillars, showcasing marquee names from that Ninth Street roster; these include Lee Krasner's botanical epic "The Seasons" (1957); Helen Frankenthaler's coastal fantasia "Seascape with Dunes" (1962); Elaine de Kooning's violent drama "Bullfight" (1959); and Joan Mitchell's romantic, eruptive topography, "Slate" (134).
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Painted mainly in yellows, it percolates with horizontal, vertical, zigzag and circular brushstrokes, supplemented by dabs and swirls overlaid with drips and drizzles of red, sea-blue, bright green, and pink, an eruptive and bubbling surface that coheres with the patient viewer's unfolding fluency in the brushwork's measured and predictable patterns.
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We Just Found Out That Mercury Is Geologically ActiveOur solar system is rife with geologic activity, from eruptive ice moons to mountainous dwarf…Read more ReadA few months back, scientists analyzing data collected during NASA's MESSENGER mission made a startling announcement: Mercury, a planet just a smidge larger than our Moon that sits blisteringly close to the Sun, is geologically active.
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Balancing out that tenderness near the night's end was a stream of the label's indelible hip-hop hits — Black Rob's "Whoa," Junior M.A.F.I.A.'s "Player's Anthem" (not on the label, but by B.I.G. affiliates), and then a chaotic, eruptive "It's All About the Benjamins," featuring the Lox and Lil' Kim, perhaps the most emblematic song of 1990s New York hip-hop excess, and here, a coronation.
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BEETHOVEN: The Universal Composer In this account of Beethoven's life, Morris's "narrative is vivid, starting with the starkly black-and-white cityscape of Bonn, where Beethoven was born in 1770, then going on to the composer's painful childhood; his emergence in his teenage years as an eruptive 'young Caliban'; his sexual shyness; his triumphs as a young man in Vienna; his deafness; and finally his fall from sometimes charming eccentricity into ugly paranoia and perhaps even psychosis," our reviewer wrote.
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Generalized eruptive histiocytoma (also known as "Eruptive histiocytoma," and "Generalized eruptive histiocytosis") is a rare cutaneous condition characterized by widespread, erythematous, essentially symmetrical papules, particularly involving the trunk and proximal extremities.
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The weakest are Hawaiian and submarine, then Strombolian, followed by Vulcanian and Surtseyan. The stronger eruptive types are Pelean eruptions, followed by Plinian eruptions; the strongest eruptions are called "Ultra-Plinian." Subglacial and phreatic eruptions are defined by their eruptive mechanism, and vary in strength. An important measure of eruptive strength is Volcanic Explosivity Index (VEI), an order of magnitude scale ranging from 0 to 8 that often correlates to eruptive types.
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Later analysis placed the epicentre north of the township of Jedey. Eruptive activity at the Duraznero vent ceased on 6 July with only degassing continuing. No eruptive activity occurred on 7 July.
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The knowledge of Heart Peaks is limited, especially its eruptive history.
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There could be systemic manifestations like pharyngitis or enlargement of lymph nodes. Most children with eruptive hypomelanosis develop no complications. The epidemiology, aetiology, clinical manifestations, complication, infectivity, and management of eruptive hypomelanosis leave much space to be investigated.
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It has been considered that they became trapped during transport in the eruptive plume.
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Non-eruptive activity however occurs in the form of surface deformation and earthquake activity.
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Other typical symptoms are eruptive xanthomas (in about 50% of patients), lipemia retinalis and hepatosplenomegaly.
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Based on time of development, they may be classified as pre- and post-eruptive enamel lamellae.
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Total eruptive volumes of at least 4,600–7,200 km3 per caldera complex (over its history) were inferred.
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Eruptive history, geochronology, and magmatic evolution of the Puyehue-Cordón Caulle volcanic complex, Chile. GSA Bulletin. 2008.
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The discovery of this mural has led to efforts to date the eruptive activity of Mount Hasan.
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Eruptive activity at Soputan typically consists of pyroclastic flows, lava flows, lava domes and Strombolian-style explosions.
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Goat Rocks is now classified as an extinct volcano, as its most recent eruptive activity was during the Pleistocene.
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Because of its eruptive history and proximity to populated areas, Ulawun has been deemed one of the Decade Volcanoes.
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Medication-induced hyperlipoproteinemia is a condition that results from the decreasing of lipoprotein lipase activity resulting in eruptive xanthomas.
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A second phase of eruptive activity has not yet occurred, and it does not necessarily follow that it will occur.
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4, 5. Three eruptive stages built the Mount Cayley massif, the second of which is named after the Vulcan's Thumb.
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Anorthoclase crystal (45 mm long) from Mt. Erebus Mount Erebus is currently the most active volcano in Antarctica and is the current eruptive zone of the Erebus hotspot. The summit contains a persistent convecting phonolitic lava lake, one of five long-lasting lava lakes on Earth. Characteristic eruptive activity consists of Strombolian eruptions from the lava lake or from one of several subsidiary vents, all within the volcano's inner crater. The volcano is scientifically remarkable in that its relatively low-level and unusually persistent eruptive activity enables long-term volcanological study of a Strombolian eruptive system very close (hundreds of metres) to the active vents, a characteristic shared with only a few volcanoes on Earth, such as Stromboli in Italy.
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GIC materials have adhesive capabilities with both enamel and dentine, long-term fluoride release and hydrophilicity when there is inadequate moisture control intra-orally, during early post-eruptive stages. However, GIC’s poorer mechanical properties suggest avoidance in stress- bearing areas. In later post-eruptive stages GIC may be valuable as sub-layer beneath composite restorations.
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The most well-observed are magmatic eruptions, which involve the decompression of gas within magma that propels it forward. Phreatomagmatic eruptions are another type of volcanic eruption, driven by the compression of gas within magma, the direct opposite of the process powering magmatic activity. The third eruptive type is the phreatic eruption, which is driven by the superheating of steam via contact with magma; these eruptive types often exhibit no magmatic release, instead causing the granulation of existing rock. Within these wide-defining eruptive types are several subtypes.
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In a similar manner, small pox, measles, chicken pox and all eruptive diseases come out as products from morbific causes within.
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Limpidness of sea-water during the above-mentioned time underwent appreciable changes, mostly on account of successive stages of eruptive activity.
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Histogram showing the eruptive history of the Mount Meager massif. The eruptive period that created the Mosaic Assemblage is shown as B on the first row. The Mosaic Assemblage is a rock unit of the Pacific Ranges of the Coast Mountains in southwestern British Columbia, Canada. It is the namesake of Mosaic Glacier, which is drained by Mosaic Creek.
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280-281 See also GVP: Grimsvotn. Eruptive history. Retrieved 29 August 2020. though not all the scientists involved are of this opinion.
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Other indicators suggestive of heightened eruptive danger, such as active fumaroles and recently discovered faults, are typical occurrences at this type of volcano.
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The volcano has an approximate rock generation rate of , lower than other arc associated volcanoes. Nevertheless, with eruptive episodes being separated by gaps of about 40,000 years between the last episodes, dangerous eruptive activity in the future is possible. However, the region surrounding the volcano is thinly populated, so major damage to infrastructure or danger to human life is unlikely.
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Mount Bromo erupted in 2004. That eruptive episode led to the death of two people who had been hit by rocks from the explosion.
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In the past 300,000 years, there have been a series of changes in magmatic composition, locus of volcanic activity, magma output rates and eruptive styles.
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Last eruptive activity is thought to be Pleistocene, about 500,000 years ago. Smithsonian Institution's Global Volcanism Program, Panay page There have been no historical eruptions.
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Belknap can be seen by tourists at the Dee Wright Observatory, which was built in-part with lava blocks from Belknap Crater. A precise determination for Belknap's age has not been made, as its early history remains obscure. Belknap has likely been built up by eruptive activity over a long period of time. Belknap Crater has had four Holocene eruptive periods confirmed by geological evidence.
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Another fissure eruption started in Holuhraun at around 05:05 GMT on the morning of 31 August 2014, in the same rift as the eruption which had occurred two days earlier. The eruptive fissure was estimated to be long. By 4 September, the total area of the lava flow was estimated at . Two new eruptive fissures formed south of the main eruption site, on 5 September.
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Diagrammatic representation of eruptive activity at the Mount Meager massif in millions of years (Ma). Height of the histogram gives a very crude indication of the size of the event. The latest event about 2,400 years ago (shown in the histograph as the latest eruption) was similar to the 1980 eruption of Mount St. Helens. Eruptive events marked with question marks are those with uncertain identity.
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Aerosol from the eruption traveled as far as Greenland, falling for as long as six years. The United States Geological Survey has referred to the 7,700 years ago Mazama eruption as the largest explosive eruption within the Cascades in the past million years, and one of the largest eruptions during the Holocene epoch. Considering Mazama's eruptive output within the past 420,000 years, it may have produced more than of eruptive volume, making it either the third or fourth most productive Quaternary volcanic center in the Cascade Range. The eruption had a Volcanic Explosivity Index of 7, as determined from eruption cloud height, eruptive volume, and qualitative observations.
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Mount Barbaro or Mount Gauro in Italy or , is one of the eruptive vents of the Phlegraean Fields, a volcanic field of Italy located in Campania.
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Model demonstrating how caldera volcanoes collapse. Most Ionian volcanoes start as steep-sided shield volcanoes. After an eruptive construct-building phase, the central region collapses to form a caldera. Since steep-sided shield volcanoes have not been observed inside collapsed calderas, this indicates a failure to reform steep-sided volcanoes after the collapse, which can be associated with various variables such as change in temperature, eruptive rate, and/or lava composition.
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Lateral explosions excavated a notch in the southeast crater wall. St. Helens reached its greatest height and achieved its highly symmetrical form by the time the Kalama eruptive cycle ended, in about 1647. The volcano remained quiet for the next 150 years. The 57-year eruptive period that started in 1800 was named after the Goat Rocks dome, and is the first time that both oral and written records exist.
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Volcanic gas emissions from this volcano are measured by a Multi- Component Gas Analyzer System, which detects pre-eruptive degassing of rising magmas, improving prediction of volcanic activity.
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Two of the pyroclastic flows were deposited as one unit, and pumice fell to build a tuff cone at the northern edge of the Crags, while lava dome A formed and magma in the eruptive conduit cooled to plug the eruptive vent. Domes B through F followed in that order, though their exact ages remain unclear. Lasting from 1125 years ago to 1060 years ago, this eruptive phase resembled the Lassen Peak eruptions in May 1915, though the Chaos Crag eruption had a magnitude 100 times greater, with an output volume of . The eruptions also created a cone made of tephra material, along with two pyroclastic flows, which had a volume of about .
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Mount Jefferson from above Scientists lack a comprehensive record of activity at Mount Jefferson, as important details have been obscured by the erosion of deposits by large glaciers. A few eruptions have been documented from the deposits that have been preserved, but the broad outline of Jefferson's eruptive history is understood, including that its activity has changed over time, producing both powerful explosive eruptions and lava flows. Historically, eruptive activity has alternated between andesitic and dacitic lavas. The volcano formed over the course of several eruptive episodes, beginning about 300,000 years ago with the formation of rocks on the western and southwestern flanks of the volcano, and lasting until roughly 15,000 years ago.
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Basalt is mostly absent at higher elevation, where andesite dominates and rhyolite and small volumes of dacite are present. During the past 11,000 years, eruptive activity at Medicine Lake Volcano has been episodic. Eight eruptions produced about of basaltic lava during a time interval of a few hundred years about 10,500 years ago. That eruptive episode was followed by a hiatus that ended with a small andesitic eruption about 4,300 years ago.
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The second eruptive period between 1,600,000 and 1,400,000 years ago produced rhyodacite tuff, breccia, lavas and domes of . This thick geological formation lies on the south and west flanks of Pylon Peak and Devastator Peak. Its western portion consists of roughly layered tephra while its eastern end represents the lava flows and subvolcanic intrusions of a partly preserved vent. Here, The Devastator Assemblage is massive and steeply truncates basal breccia from the first eruptive period.
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He currently serves as a member of the United States Geological Survey's Volcano Hazards Response Team, and has responded to potentially eruptive volcanoes in Japan, the Philippines, Indonesia, and Chile.
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Flare sprays are a type of eruption associated with solar flares. They involve faster ejections of material than eruptive prominences, and reach velocities of 20 to 2000 kilometers per second.
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The eruptive centers Amirani and Maui can be found northwest, as well as Maui Patera. Gish Bar Patera is located toward the northeast.NASA World Wind 1.4. NASA Ames Research Center, 2007.
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The Koenigsberger ratio is the proportion of remanent magnetization relative to induced magnetization in natural rocks. It was first described by .Koenigsberger, J. G. (1938). Natural residual magnetism of eruptive rocks.
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Volcanism in the central segment began at least 4.0 million years ago at the deeply dissected Mount Cayley massif. This eruptive period, lasting until 0.6 million years ago, produced dacite lava flows and pyroclastic breccia. A central plug dome forming the summit spires of Mount Cayley represents the youngest feature that formed during this eruptive period. Subsequent activity 0.3–0.2 million years ago began with the eruption of a dacite lava flow into the Shovelnose Creek valley.
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The volcano erupted at least three times, emptying the magma chamber below. All three eruptions produced porphyritic basalt, although rocks from the first eruptive phase are almost aphanitic. The first eruption was a basaltic flow that created the extensive lava fields visible from Interstate 40. Due to evidence from intrusive structures, it is believed that the cinder cone was formed around this time, although rocks from this eruptive phase are not present on the surface of the cinder cone.
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Orthodontic tooth movement can be used to erupt teeth in adults. If moderate eruptive forces are applied, the entire eruptive apparatus will move in unison with the tooth. As such, the units required must be extruded a distance equal to or slightly longer than the portion of sound tooth structure that will be exposed in the following surgical treatment. Once stabilised, a full-thickness flap is then elevated and osseous recontouring is performed to expose the required tooth structure.
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Mount Fuji, Japan All stratovolcanoes and shield volcanoes have a tendency to form a cone at the surface. However, stratovolcanoes are able to form steeper sides whilst shield volcanoes only form very flat cones. The reason for this is that stratovolcanoes are composed largely of solid, eruptive material, whereas shield volcanoes are built up mainly by fluid lava flows. Over the course of time, after several eruptions, a cone of debris forms from the eruptive material.
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This forms part of the much larger Northern Cordilleran Volcanic Province, which extends from the Alaska–Yukon border to near the port city of Prince Rupert, British Columbia. Eruptive activity at The Volcano is relatively young compared to most other volcanoes in the Northern Cordilleran Volcanic Province. Geologic studies have shown that The Volcano and its eruptive products were emplaced in the past 400 years; this is well after the last glacial period, which ended about 10,000 years ago.
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On April 18, a portable seismometer began to record much stronger volcanic tremors that indicated a change in eruptive style from lava fountains back to Strombolian activity. Spatter was discharged every 3–8 seconds with loud gas bursts. In addition, the eruptive rate increased and the upper 300 meters of the channel was largely pahoehoe lava. The eruption rates, estimated from the dimensions and flow rates in the channel, were between 4 and 8.5 million cubic meters per day.
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Klyuchevskaya appeared 6,000 years ago.Entre volcans et saumons : voyage d’exception au Kamtchatka. Atlantico. Retrieved on 2018-10-25. Its first recorded eruption occurred in 1697,Global Volcanism Program: Kliuchevskoi, eruptive history. Volcano.si.edu.
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It is part of the Wrangell Volcanic Field, which extends for more than across Southcentral Alaska into the Yukon Territory, and has an eruptive history spanning the time from Pleistocene to Holocene.
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However, some eruptive activity has continued in the High Cascades; there is one lava flow in the McKenzie Pass area to the west of Black Butte, which is only 1,500 years old.
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Tuberoeruptive xanthoma (ILDS E78.210) is clinically characterized by red papules and nodules that appear inflamed and tend to coalesce. Tuberous xanthomata are considered similar, and within the same disease spectrum as eruptive xanthomata.
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The first phase of the eruption lasted from 20 March to 12 April 2010 and was characterised by olivine basaltic andesite lava flowing from various eruptive vents on the flanks of the mountain.
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Third, Zamama's third plume was actively erupting while Galileo was on its 14th orbit around Jupiter. New deposits enlarged to and are centered east of the eruptive center. Total affected area was about .
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Arenal Volcano area is an important watershed for the Arenal Lake Reservoir. The reservoir's water is used for hydroelectric power. It is also connected to the national system. Arenal has several eruptive vents.
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At least three phases of eruptive activity have been identified at Mount Price. The first event 1.2 million years ago deposited hornblende andesite lava and pyroclastic rocks on the floor of a cirque-like basin after an Early Pleistocene glacial event. The Black Tusk, a deeply dissected stratovolcano north of Mount Price, was also active during this period. Because older volcanic events have not been identified in the Garibaldi area, this is the oldest known eruptive period in the Garibaldi Lake volcanic field.
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Mazama was covered with incandescent pumice. The extreme weight of eruptive material began to push down on the volcano's summit, similar to a piston. Eventually, the top of Mazama's magma chamber subsided, and concentric openings formed by the summit, producing smaller vents surrounding the main eruptive cone. Pumice ejected from these new fractures created rapid pyroclastic flows that coursed down all the sides of Mazama, traveling over tall ridges and summits of subfeatures and extending tens of miles from their vents.
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The Mount Cayley massif has experienced volcanic eruptions sporadically for the last 4,000,000 years, making it one of the most persistent eruptive centres in the Garibaldi Volcanic Belt. Three primary eruptive stages in the history of the massif have been identified. The Mount Cayley and Vulcan's Thumb stages occurred between 4,000,000 and 600,000 years ago with the construction of the stratovolcano and plug domes. A 300,000-year-long period of quiescence followed, during which prolonged erosion destroyed much of the original volcanic structure.
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Queensland, Western Australia and the majority of the Northern Territory and South Australia. During its eruptive periods, population numbers can reach hundreds of individuals per hectare. Less information is known about the distribution of the long-haired rat in a non-eruptive period however it is known that they can spend only 13 days without green vegetation and water therefore their distribution is thought to be much more restricted and centered on water and food sources. See external link for distribution map.
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These volcanics were erupted under more than of glacial ice to produce subglacial eruptions. Hoodoo Glacier and lava flows on the flanks of Hoodoo Mountain. During the second eruptive phase 80,000 years ago, eruptions were no longer subglacial, but the volcano was surrounded by ice at least thick. Lava flows during this eruptive phase melted some of the thick glacial ice and ponded around the perimeters of Hoodoo Mountain, which quickly solidified to form a barrier behind which more lava piled up.
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Present day global emissions of volcanic gases to the atmosphere can be characterized as emissions during eruptions and emissions during non-eruptive activity. Although all volcanic gases are emitted to the atmosphere, the emissions of CO2 (a greenhouse gas) and SO2 have received the most study. It has long been recognized that SO2 emissions during eruptions are much less than during passive degassing. Fischer et al (2019) estimated that, from 2005 to 2015, SO2 emissions during eruptions were 2.6 tera grams (1012g or Tg) per year and during non-eruptive periods or passive degassing were 23.2 ± 2Tg per year. During the same time interval, CO2 emissions from volcanoes during eruptions were estimated to be 1.8 ± 0.9 Tg per year and during non-eruptive activity were 51.3 ± 5.7 Tg per year.
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No eruptive activity has occurred at Amiata during the Holocene, but thermal activity including cinnabar mineralization continues at a geothermal field near the town of Bagnore, at the SW end of the dome complex.
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Cerro Solo is a large stratovolcano on the border between Argentina and Chile, west of Ojos del Salado. It consists of nine eruptive centers and is covered in light-colored rhyodacite pyroclastic flow deposits.
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Another ignimbrite, Los Colorados, is located at the edge of the Amarga caldera but its eruptive centre is unknown. After its formation, lava flows from Cerro El Condor overran the floor of the caldera.
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It has also been suggested that a hamartomatous process could explain eruptive syringomas. A hamartoma of pluripotent stem cells could precede the pathological process. Syringomas may also be under hormonal influence explaining the female predominance.
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Marian Grzybowski (15 June 1895 in Chardzhou – 11 December 1949) was a Polish dermatologist. He authored more than 80 scientific publications. He first described a variant of keratoacanthoma, called today generalized eruptive keratoacanthoma of Grzybowski.
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The name "Sabancaya" is Quechua and means tongue of fire or spitting volcano, likely a reference to the eruptive activity. The name is attested from 1595, implying that volcanic activity was observed since that date.
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The current cycle of eruptive activity began in middle Pleistocene time with extrusion of andesitic lava flows, perhaps from multiple vents. By the late Pleistocene, central-vent volcanism had initiated construction of a small stratovolcano.
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The total eruptive volume was roughly . The development, eruption, and close monitoring of Axial Seamount provided a fertile model on submarine volcanic eruptions to scientists; several scientific papers on the topic were published soon after.
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TNMD is highly expressed on messenger and protein levels in tendons and ligaments, but has also been found in other tissues. \- In tendon development first signals are detectable as early as E9.5, but upregulated from E14.5 onwards, marking the differentiated stage of tendon progenitors. \- Mouse periodontal ligaments demonstrated tenomodulin protein expression at 3 and 4 weeks postnatal, a time period corresponding to molar eruptive and post- eruptive phases when the teeth become functional. \- Other tendinous tissues known to express Tnmd are the diaphragm and chordae tendineae cordis.
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Indian Heaven features both polygenetic and monogenetic volcanic activity; many of its volcanoes have only erupted once before coming extinct, while others have erupted several times. Approximately 50 eruptive centers lie within the Indian Heaven field, which also has approximately 40 lava flows. The field's eruptive output totals , with sporadic activity taking place for the past 700,000 years. The last volcanic activity in the field produced a large cinder cone, Big Lava Bed, as well as a voluminous lava and scoria flows about 9,000 years ago.
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Histogram showing the eruptive history of the Mount Meager massif. The eruptive period that created The Devastator Assemblage is shown as a rectangle between 1.4 and 1.6 Ma. The Devastator Assemblage is a geological formation comprising a portion of the Mount Meager massif in southwestern British Columbia, Canada. It is named after Devastator Peak (also known as The Devastator), the lowest and southernmost subsidiary peak of Meager. The south and west flanks of Pylon Peak and Devastator Peak are made of The Devastator Assemblage rocks.
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The eruption that created the caldera was comparable in volume to the one that produced Crater Lake in Oregon. Between 1.15 and 0.99 million years ago, dike-fed eruptions produced rhyodacitic lava domes and lava flows inside the caldera. Another volcanic phase 1.1 to 0.5 million years ago emplaced over 60 andesite dikes, the eruptive products of which have since been stripped away by glacial erosion. It is speculated that the eruptive rocks from this volcanic phase formed a large andesitic cone now completely removed.
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Each eruptive cycle was separated from one another by long periods of dormancy and minor activity, during which, glaciers eroded the mountain to below . Potassium-argon dating has identified three such eruptive periods; the first occurring 520,000 to 500,000 years ago, the second 450,000 years ago, and the third 40,000 to 10,000 years ago. Most of these eruptions and therefore most of the volcano, consist of lava flows with little tephra. The loose material that makes up much of Adams' core is made of brecciated lava.
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The composition of the current eruptive products of Erebus are anorthoclase-porphyritic tephritic phonolite and phonolite, which are the bulk of exposed lava flow on the volcano. The oldest eruptive products consist of relatively undifferentiated and nonviscous basanite lavas that form the low broad platform shield of Erebus. Slightly younger basanite and phonotephrite lavas crop out on Fang Ridge—an eroded remnant of an early Erebus volcano—and at other isolated locations on the flanks of Erebus. Erebus is the world's only presently erupting phonolite volcano.
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Cinder cone volcanoes are typically monogenetic, meaning that they only undergo one eruptive period before ceasing activity forever. These eruptions often consist of the ejection of tephra, though they may also generate lava flows, which often originate from vents near the base rather than the summit of the volcanic edifice. The summit of Cinder Cone has a crater with a double rim (photo), probably created by two different phases of one eruptive period. The cone also has a widespread ash deposit identifiable for from the cone.
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Plinth Peak was also formed during the Plinth Assemblage eruptive stage and is mostly composed of prominent columnar or partly jointed lava flows. Its north ridge and flat-topped summit contain three areas of steep flow layering and subhorizontally-oriented columnar jointing. These areas are possibly the remains of volcanic plugs or lava domes that were the northern source of Plinth Assemblage lava flows. The Mosaic Assemblage, a sparsely porphyritic plagioclase-augite-olivine basalt and trachybasalt formation, also formed during the fourth eruptive period.
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To the west is the eruptive center Amirani, and to the north is Skythia Mons. To the east are Gish Bar Patera, Gish Bar Mons, and Estan Patera.NASA World Wind 1.4. NASA Ames Research Center, 2007.
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Failure to reform shield volcanoes is caused by failure to supply magma through the magma chamber. These interpretations might be a sign that current shield volcanoes will follow this pattern and transform to caldera- forming eruptive sites.
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Mount Price and one of the Battleship Islands reflected in the clear water of Garibaldi Lake Mount Price, one of the three principal volcanoes in the southern segment, formed during three periods of eruptive activity. The first eruptive period 1.2 million years ago constructed a hornblende andesite stratovolcano on the floor of a cirque-like basin. During the Middle Pleistocene about 300,000 years ago, volcanism shifted westward and constructed the nearly symmetrical stratovolcano of Mount Price. Episodic eruptions produced andesite and dacite lavas, as well as pyroclastic flows from Peléan activity.
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The southern group is made from rock that is 700,000 to 1,700,000 years old, while the northern group is made from rock that is 13,000 to 700,000 years old along the southwestern rim of an older caldera. Eight eruptive events have occurred in the Northern Hakkōda Volcanic Group since 4,000 BCE, including phreatic and vulcanian eruptions. Four eruptive events occurred at the summit of Ōdake, with another possible eruption at Ōdake. The three most recent eruptions occurred at Jigokunuma on the southwestern foot of Ōdake near Sukayu Onsen during the 13th to 17th centuries.
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The existence of olivine, orthopyroxene and spinel xenocrysts in Level Mountain basalt suggest that volcanism at the complex originated from the upper mantle. Hiatuses of up to a million years or more can be expected between periods of volcanic activity at Level Mountain. Geologic map of Level Mountain showing eruptive products and eruptive centres Like several other volcanoes in northern British Columbia, Level Mountain was volcanically active during past glacial periods. Its involvement with glaciation resulted in several interactions between magma and ice, affording multiple examples of glaciovolcanic processes.
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There are no historical eruptions within the Natib caldera complex. Studies in 1991 (Panum and Rayem) indicate that the last eruptive activity was probably Holocene to upper Pleistocene. An earlier study in 1971 (Ebasco Services) dated the eruptive products between 69,000 +/- 27,000 years old. A recent study by Dr. Kevin Rodolfo of the Department of Earth and Environmental Sciences at the University of Illinois at Chicago, had Mount Natib's latest eruption between 11,000 and 18,000 years ago after studying a prehistoric pyroclastic flow from the volcano that entered Subic Bay in Zambales province.
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The lava flows around Darwin are homogenous, apparently because of its young age, and they have a similar chemical composition to those of the Galápagos Spreading Center.Role of Plume-Ridge Interaction in Magma Genesis III: Darwin Island Darwin is believed to have had at least two eruptive periods in its history, depositing two tuff layers separated by plagioclase ultraphyric basalt. Evidence also exists to suggest that Darwin Island is the remains of what was once a much larger edifice. Since the eruptive phase this would have been eroded.
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La Grille appears as a mountain range running from north to south, reaching a slag height of meters on average, and covered in stratovolcano cones, giving the volcano a maximum altitude of meters. Unlike its neighbour Karthala, La Grille does not have caldera. Different eruptive vents are located along the fissures that run along the volcano from north to south, parallel to the ridge of the mountain, and other cracks along the coast. Lava basalt sometimes escapes from these eruptive vents, sometimes reaching the sea to the east, north and west sides of the volcano.
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Roșia Poieni represents the largest copper reserve in Romania and the second largest in Europe having estimated reserves of 1.5 billion tonnes of ore grading 0.36% copper. It is enclosed by eruptive sub-volcanoes Miocene rocks (micro-diorite or Fundoaia andesites). The Fundoaia body has the shape of a vertical column of in height (+ → ) and in horizontal plane having the following dimensions: ÷/÷. The eruptive body comes in contact (through the tectonic breccia) with andesite necks (Poieni, Curmatura, Melciu, Piatra Tichileu, and Jgheabului Hills) and with sedimentary Cretaceous rocks.
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The surrounding area has been inhabited by indigenous peoples for more than 7,000 years while geothermal exploration has taken place there for the last four decades. Part of the Garibaldi Volcanic Belt, the Mount Cayley massif was formed by subduction zone volcanism along the western margin of North America. Eruptive activity began about 4,000,000 years ago and has since undergone three stages of growth, the first two of which built most of the massif. The latest eruptive period occurred sometime in the last 400,000 years with lesser activity continuing into the present day.
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Parts of this ancestral cone were fragmented and transported by glaciers 14,000–18,000 years ago during the last glacial period of the current ice age. The second eruptive period, the Cougar Stage, started 20,000 years ago and lasted for 2,000 years. Pyroclastic flows of hot pumice and ash along with dome growth occurred during this period. Another 5,000 years of dormancy followed, only to be upset by the beginning of the Swift Creek eruptive period, typified by pyroclastic flows, dome growth and blanketing of the countryside with tephra.
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Blood samples of a young patient with extreme hypertriglyceridemia Most people with elevated triglycerides experience no symptoms. Some forms of primary hypertriglyceridemia can lead to specific symptoms: both familial chylomicronemia and primary mixed hyperlipidemia include skin symptoms (eruptive xanthoma), eye abnormalities (lipemia retinalis), hepatosplenomegaly (enlargement of the liver and spleen), and neurological symptoms. Some experience attacks of abdominal pain that may be mild episodes of pancreatitis. Eruptive xanthomas are 2–5 mm papules, often with a red ring around them, that occur in clusters on the skin of the trunk, buttocks and extremities.
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The Northern group is composed of two cones, formed 126,000-90,000 years ago; the Southern group is larger, with two cones in the lagoon itself, and formed over a much larger and undetermined span of time. Most volcanic complexes in the field have a well-preserved scoria cone and lava apron, dotted with eruptive vents and lava flows. 42 eruptive units can be seen on the ground today. The San Quintín field is the only known location of intraplate-type mafic alkalic volcanism on the Baja California peninsula.
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St. Helens produced an additional five explosive eruptions between May and October 1980. Through early 1990, at least twenty-one periods of eruptive activity had occurred. The volcano remains active, with smaller, dome-building eruptions continuing into 2008.
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Eruptive variable stars show irregular or semi-regular brightness variations caused by material being lost from the star, or in some cases being accreted to it. Despite the name these are not explosive events, those are the cataclysmic variables.
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The only activity present in the Northern Cordilleran Volcanic Province has been occasional earthquakes and constant boiling of hot springs. However, a high potential exists for renewed eruptive activity that could threaten life and property in the volcanic zone.
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By this time 153 people had been reported to have been killed and 320,000 were displaced. Later the eruptive activities again increased requiring a continuation of the Level 4 alert and continued provision of exclusion zones around the volcano.
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Nine distinct eruptive centres from different geological ages, ranging from mid-Pliocene to Pleistocene, have contributed to the formation. No single model of the island's geological evolution can, therefore, be ascertained.United Nations (2000). "Saint Kitts and Nevis: Executive Summary".
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By mid-afternoon, eruptive activity began to decrease at the uppermost vents between . At 4:41 p.m., a new fissure opened up at the elevation. This fissure rapidly migrated both uprift and downrift, so that by 6:30 p.m.
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The deeply carved circular valleys also display the bounding faults of a buried, cogenetic caldera approximately across. More than of rhyolite and trachyte was erupted during the Spectrum Range dome eruptive period, with its activity ending 2,500,000 years ago.
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Earlier eruptive events involving a lava flow that was subsequently offset by a fault zone named the Cayambe-Chingual fault by 110m occurred 9.67 ka BP, and another involving a pyroclastic flow was dated at 37.22 ± 0.63 ka BP.
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On 18 November 2018, Volcán de Fuego entered a new eruptive and violent phase that prompted preventive evacuations of approximately 4,000 people from communities near the volcano.Guatemala volcano: Satellite captures video of Fuego eruption from space. The Independent. 20 November 2018.
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Mount Rainier last erupted between 1824 and 1854, but many eyewitnesses reported eruptive activity in 1858, 1870, 1879, 1882, and in 1894 as well. Mount Rainier has created at least four eruptions and many lahars in the past 4,000 years.
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Because of its proximity to populated areas and its eruptive history, the volcano was designated a Decade Volcano, worthy of close study to prevent future natural disasters. All volcanoes of the Philippines are part of the Pacific Ring of Fire.
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Eruptive history of the volcano at Ritter Island, in Cooke-Ravian Volume of Volcanological Papers, pp. 115–123, ed. Johnson, R. W; Geological Survey Papua New Guinea, Memoir 10. damage was inflicted on islands several hundreds of kilometres from Ritter Island.
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Eruptive hypomelanosis is a novel paraviral exanthem suspected to be related to viral infections. Most patients are young children aged two to ten. Most children develop prodromal symptoms similar to common cold or influenza. Small, monomorphous, and hypopigmented macules then erupt.
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Idiopathic eruptive macular pigmentation is a skin condition developing in young persons, with an average age of 11, characterized by asymptomatic widespread brown to gray macules of up to several centimeters in diameter on the neck, trunk, and proximal extremities.
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The eruptive products consisted of basaltic andesite which surprised the scientists as these more evolved rocks are neither typical for Bárðarbunga nor for Grímsvötn, both more connected to basaltic volcanism. Some scientists thought that Gjálp could be an independent volcano.
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Craters have diameters of . The total volume of these cones is less than . Weak pyroclastic activity probably accompanied the eruptive activity. Presumably, low intensity explosive activity built the cones, starting from the northeast cone and ending with the southwest cone.
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At least 63 volcanic events have occurred in the Garibaldi Lake volcanic field in the last 1.3 million years. Since the early Holocene epoch, there has been no eruptive activity. Future eruptions of Mount Price will probably be similar in character to those that have occurred throughout its 1.2 million year eruptive history. The minimum annual probability of an eruption occurring in Canada is about one every 200 years; for an effusive eruption the probability is about one every 220 years and for a large explosive eruption the probability decreases to about one every 3,333 years.
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Alfred François Antoine LACROIX (1863-1948) Annales.org His studies of the eruptive rocks of Corsica, Santorini and elsewhere; his researches on the artificial reproduction of eruptive rocks, and his treatise on the optical characters of feldspars deserve special mention; but he was perhaps best known for the joint work which he carried on with his friend Auguste Michel-Lévy.Auguste MICHEL-LEVY (1844-1911) Annales.org His chief publications were: Santorin et ses éruptions (1879), Minéralogie micrographique : roches éruptives françaises (1879) and Synthèse des minéraux et des roches (1882); the latter two works written in collaboration with Auguste Michel-Lévy.
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Mount Meager, located north of Vancouver, is a peak of the Mount Meager massif. This is a group of coalescent stratovolcanoes and the largest volcanic centre in the Garibaldi Volcanic Belt. It comprises about of eruptive rocks that were deposited during four distinct eruptive periods, the first beginning 2.2 million years ago. During the present period (beginning 150,000 years ago), it has erupted more than five times, producing ash falls, pyroclastic flows, lava flows and lahars. The only identified Holocene eruption was in about 410 BC and created a diverse sequence of volcanic deposits well exposed along the Lillooet River.
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There is a chain of spatter cones about south of the Blue Lake Crater, which display a similar alignment north–northeast for . The chain runs for in length between Blue Lake Crater and Mount Washington and lies south of another vent with a circular crater that is deep, which likely only erupted gas. Their eruption products show petrographic similarities to Blue Lake eruptive material, suggesting that their eruptive activity overlapped in time. Erupted tephra from both is moderately porphyritic with 1 percent olivine phenocrysts about across and 10–15 percent plagioclase phenocrysts that are slightly larger at up to across.
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The volcano does not show evidence of producing lahars. Eruptive activity began at an eruptive vent by Diamond Peak's northern summit, and shortly after, eruptions commenced at a second, slightly higher vent closer to the southern summit. Though Diamond Peak's eruptions always produced olivine-rich basaltic andesite, they likely grew more rich in silicon dioxide over time, ranging from 55 to 58 percent silicon dioxide. Lava flows from the volcano vary from in thickness, rich in porphyritic rocks like olivine, plagioclase, and clinopyroxene; there is no silicic rock (rich in silica) in the Diamond Peak vicinity.
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During the most recent eruptive episode between 3000 and 900 years ago, eight eruptions produced approximately of lava ranging in composition from basalt to rhyolite. Late Holocene lava compositions include basalt and andesite, but silicic lavas dominate. Eruptive activity during Holocene time has included numerous rhyolite and dacite lava flows erupted at high elevations inside and outside the caldera; cinder cones and associated lava flows of basalt and basaltic andesite have resulted from eruptions at vents on the flanks of the shield. Most vents are aligned along zones of crustal weakness that trend northeast to northwest.
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Relative age relationships both within and between the major eruptive centers are difficult to determine due to the complex nature in which these flows coalesce and inter-finger. Each volcano appears to have had an extensive period of eruptive activity with several major phases creating large flow fields and more localized activity occurring both at vents on the flanks of the volcanoes and at their summits. Geologic mapping shows a general progression from upland terrain to volcanic plains and then to shield volcanoes and flow fields but also reveals a complex interplay between volcanic and tectonic processes.
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A dormancy of about 4,000 years was broken around 2500 BCE with the start of the Smith Creek eruptive period, when eruptions of large amounts of ash and yellowish-brown pumice covered thousands of square miles. An eruption in 1900 BCE was the largest known eruption from St. Helens during the Holocene epoch, depositing the Yn tephra. This eruptive period lasted until about 1600 BCE and left deep deposits of material distant in what is now Mount Rainier National Park. Trace deposits have been found as far northeast as Banff National Park in Alberta, and as far southeast as eastern Oregon.
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The main volcanics at Hoodoo Mountain are phonolite and comendic trachyte lavas and hyaloclastites, although some pyroclastic rocks also exist. The trachyte and comendic magmas erupted from Hoodoo Mountain and other Northern Cordilleran volcanoes are thought to have been created by fractionation of primary alkali basaltic magma in crustal reservoirs. The estimated volume of erupted material from Hoodoo Mountain is , and at least six phases of eruptive activity are recognized at the volcano. The first phase of eruptive activity occurred 85,000 years ago in the Late Pleistocene stage of the Pleistocene epoch, producing lava flows, lava domes, and breccia deposits.
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During the fourth phase of eruptive activity 54,000 years ago, eruptions were again no longer subglacial. Lava flows from this phase of activity overlie pyroclastic deposits from the third phase of activity and ice-dammed lava from the second phase of activity. Between 54 and 30 thousand years ago, the fifth phase of eruptive activity occurred subglacially and produced two distinct types of lava-breccia associations. The first subglacial eruption between 54 and 40 thousand years ago produced lava domes and monomict breccia, while the other subglacial eruption between 40 and 30 thousand years ago took place under thinner glacial ice.
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The final phase of eruptive activity was effusive in nature with no explosive activity (VEI-0). This effusive volcanism produced lava flows with well-preserved lava channels on the northwest and southwest flanks of Hoodoo Mountain in the early Holocene epoch and are largely unglaciated, suggesting the final eruptive phase occurred in an ice-free environment. These lava flows originated from the mountain's flat- topped summit and volcanic vents on its flanks. Geologists do not always agree on the dates of these more recent eruptions, some dating them to nine thousand years ago, others to as recently as seven thousand years ago.
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There are uncertainties in the eruptive record in the first half of the 17th century due to the Mapuche and Huilliche uprising which led to the surrender or abandonment of Spanish settlements during the destruction of the Seven Cities.Petit-Breuilh 2004, p. 52.
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Thornton mentions that Krakatoa was known as "The Fire Mountain" during Java's Sailendra dynasty, with records of seven eruptive events between the 9th and 16th centuries. These have been tentatively dated as having occurred in 850, 950, 1050, 1150, 1320, and 1530.
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The thermophilic bacterium Thermus aquaticus, important because it produces an enzyme used in polymerase chain reaction laboratory procedures central to modern molecular biology, was first isolated from Mushroom Pool, a non-eruptive hot spring a few hundred feet from White Dome Geyser.
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To the southwest is the eruptive center Amirani, and to the southeast are Gish Bar Patera, Gish Bar Mons, and Estan Patera.NASA World Wind 1.4. NASA Ames Research Center, 2007. Shango was the site of a major surface change between 2001 and 2007.
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There are no historical eruptions from the volcano with the last eruptive activity dated as Holocene as reported by the Global Volcanism Program. Thick lava flows from that period are present on the flanks of Mount Masaraga, an understudied volcano in the Philippines.
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The overall results of the Avellino eruption were catastrophic and widespread. The deposit thickness of ash and other eruptive material ranges from 15m close to the vent to 50 cm around Avellino, and creating a subaquaeous debris-flow in the bay of Naples.
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After a brief pause, it erupted again on August 8, 1934, and has not completely quelled ever since, with heavy eruptive periods occurring in 1934–1937 and 1941–1942. Eruptions at Sangay exhibit strombolian activity, producing ashfall, lava flows, pyroclastic flows, and lahars.
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It has a diameter of . Eruptive activity here probably coincided with glacier activity during the Pliocene, as evidenced by moraines in the area. Ages of 5.3 to 1.6 mya have been estimated via potassium-argon dating of the andesite lavas and subvolcanic rocks.
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Subsequent cruises and analysis showed that the volcano had generated lava flows up to thick, and the total eruptive volume was found to be . Axial Seamount erupted again in April 2011, producing a mile-wide lava flow. There was another eruption in 2015.
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Wrangell measures in height. It was built by a series of large lava flows from 600,000 to 200,000 years ago. Three comparatively modest eruptive episodes were reported in 1784, 1884–85 and 1900. The gently sloping dome features an ice-filled summit caldera measuring by .
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Mount Fee rising above adjacent mountainous terrain. This view of the mountain is from the south. At least three phases of eruptive activity have been recognized at Mount Fee. The only exposed remnant of Fee's earliest volcanic activity is a minor outcrop of pyroclastic rock.
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Fallout from the eruption continued for roughly three years, though the major eruption only occurred for a few days. The eruption is thought to have occurred during autumn, as inferred from pollen data. The eruptive activity that led to Mazama's collapse proceeded in two phases.
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Although the first eruptive period is generally estimated to have started about 2,200,000 years ago, two andesite eruptions may have occurred about 2,400,000 and 2,600,000 years ago. The first might have produced lava flows and breccia, whereas the latter may have erupted mainly breccia.
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The rest are polygenetic shield volcanoes. About 80 percent of the lava erupted by Indian Heaven volcanoes consists of basalt; it represents the most voluminous Quaternary basalt produced by a volcanic field in the Cascade Arc north of Newberry Volcano in Oregon, with an eruptive output volume between . Basalt composition varies from low-potassium high-alumina olivine tholeiite to calc- alkaline, shoshonite, and alkaline intraplate compositions, though olivine- bearing basalt with different amounts of porphyritic plagioclase dominates. Volcanoes within the field have produced smaller amounts of basaltic andesite and andesite with silicon dioxide compositions up to 59 percent, though dacite is not very common among Indian Heaven eruptive products.
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The majority of seamounts have already completed their eruptive cycle, so access to early flows by researchers is limited by late volcanic activity. Ocean-ridge volcanoes in particular have been observed to follow a certain pattern in terms of eruptive activity, first observed with Hawaiian seamounts but now shown to be the process followed by all seamounts of the ocean-ridge type. During the first stage the volcano erupts basalt of various types, caused by various degrees of mantle melting. In the second, most active stage of its life, ocean-ridge volcanoes erupt tholeiitic to mildly alkalic basalt as a result of a larger area melting in the mantle.
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Weathering, fine grain size, and glassy content mean that there are limitations to argon–argon dating for the field as well. Recent research suggests that eruptive activity at the Boring Lava Field began between 2.6 and 2.4 million years ago, yielding far-reaching basalt lava flows, the Highland Butte shield volcano, a number of monogenetic vents, and one andesitic lava flow. These took place near the southern Portland Basin, and were followed by about 750,000 years of quiescence. About 1.6 million years ago, eruptive activity resumed to the north of the previously active area, with alkalic basalt lava flows generating the Mount Scott shield volcano.
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In total, the Belknap shield and its multiple vents were formed in less than 1,500 years, its last eruptive episode finishing about 1,500 years ago. Belknap formed on the lower slopes of Mount Washington, a highly eroded volcano, and is one of the larger mafic (rich in magnesium and iron) volcanoes in the Sisters Reach. Belknap consists of a shield volcano and pyroclastic cone and consists of basaltic and basaltic andesite lava with sub-alkaline composition, and it is characteristic of High Cascade volcanism. Well-preserved, its core is made of cinder materials; its eruptive deposits have well-preserved pressure ridges (tumuli) and levees.
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The ancestral and modern stages differ primarily in the composition of the erupted lavas; ancestral lavas consisted of a characteristic mixture of dacite and andesite, while modern lava is very diverse (ranging from olivine basalt to andesite and dacite). St. Helens started its growth in the Pleistocene 37,600 years ago, during the Ape Canyon stage, with dacite and andesite eruptions of hot pumice and ash. Thirty-six thousand years ago a large mudflow cascaded down the volcano; mudflows were significant forces in all of St. Helens' eruptive cycles. The Ape Canyon eruptive period ended around 35,000 years ago and was followed by 17,000 years of relative quiet.
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Such ice- marginal lava flows are anomalously thick and are normally bounded by steep cliffs with fine-scale cooling joints and much volcanic glass. These ice- marginal lava flows form the massive lava cliffs near the base of Hoodoo Mountain and are among Hoodoo's most prominent features. The third eruptive phase between 80 and 54 thousand years ago was followed by explosive activity that produced pyroclastic flows down the northern and western flanks of the mountain to create welded and unwelded ignimbrite deposits up to thick. This explosive activity is one of the few explosive eruptions throughout Hoodoo Mountain's eruptive history, and could have been caused by magma breaching thinner ice.
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It accumulated over at least three eruptive periods, beginning 800,000 years ago (0.8 mya) and lasting until 150,000 years ago (0.15 mya). The caldera's dimensions are by , and it has an elevation of . Activity from the caldera has produced many other stratovolcanoes to form a complex volcano.
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This indicates a common water chemistry, but their eruptive behaviors do not affect each other. Pink Geyser is susceptible to seismic activity. Before the 1983 Borah Peak earthquake, it only erupted twice a day. Following the quake, its interval shortened to between 5 and 7 hours.
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Where it is covered by a sheet of eruptive rock (charrah), it is protected from erosion. Nubian Sandstone frequently includes strata of clay and shale and thin seams of coal or lignite. This indicates that it was deposited in seas that were relatively shallow at the time.
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The 2007 eruption continued intermittently into 2008. At the end of February it was reported to be gathering strength, with a major outburst taking place on 5 March. Periods of inactivity were followed by eruptions on 8 and 17 April. Eruptive activity continued until late August 2008.
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Abyss Pool has a depth of . The pool erupted for the first time in recorded history between August 1987 and September 1991 and again between December 1991 and June 1992. The eruptions were between and high. Since 1992, the pool has returned to its non-eruptive state.
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Major cones in the field are Cerro Contreras, Cerro Fermín, Cerro Negro, Cerro Ventana, Cerro Volcán and Pinchuleu. Of these Cerro Negro is the highest with altitude. The field's products include lava and tephra. In total 26 cones and 9 eruptive centres have generated of eruption products.
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All told there may have been up to of material ejected in this cycle. Some 400 years of dormancy followed. St. Helens came alive again around 1200 BCE — the Pine Creek eruptive period. This lasted until about 800 BCE and was characterized by smaller-volume eruptions.
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During the collapse, the former Halemaumau overlook and its parking lot were lost when segments of the crater rim slumped into the crater. The summit collapse events ceased abruptly on August 2, 2018, two days before the eruptive activity on Kīlauea's east rift zone decreased significantly.
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Steamboat does not lie dormant between eruptions, instead displaying minor eruptions of approximately 40 feet (12 m). Norris Geyser Basin periodically undergoes a large-scale, basin-wide thermal disturbance lasting a few weeks. Water levels fluctuate, and temperatures, pH, colors, and eruptive patterns change throughout the basin.
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In contrast, lava from the summit flowed over pyroclastic rocks and lava flows of the explosive phase. Mount Downton and Itcha Mountain were formed during this eruptive period. The final volcanic event of the post-explosive phase produced thick trachyte lava flows on the western flank.
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In dentistry, overeruption is the physiological movement of a tooth lacking an opposing partner in the dental occlusion. Because of the lack of opposing force and the natural eruptive potential of the tooth there is a tendency for the tooth to erupt out of the line of the occlusion.
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There advantage is use during any stage of post-eruptive breakdown, but evidence of their efficacy is limited. Although the PMC has evidence to show that it is well accepted, a few of the children and their carers expressed their concerns about the metallic appearances of the restoration.
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Mount McLouglin's prominence has made it a landmark to Native American populations for thousands of years. McLoughlin consists largely of basaltic andesite. It underwent three major eruptive periods before its last activity took place between 30,000 and 20,000 years ago. It is not currently monitored for activity or deformation.
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In the first decade of the 20th Century two diseases carried Schamberg's name. Today only one does. In 1901, Schamberg described a new eruptive skin disorder, which was prevalent in the spring and fall. The condition recurred every year in and around Philadelphia, but its cause was unknown.
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Carmelo Crater is deeply dissected on its south side by the younger Sherman Crater. This crater is south of the summit, and its ice- covered floor is below the summit ice dome. This crater is the site of all Holocene eruptive activity. Hundreds of fumaroles vent gases, primarily , , and .
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Eventually switching to andesite, it may have been built over several eruptions or even eruptive periods, judging from the silicic nature of its rock. It is currently inactive, having been since approximately the time Mount Mazama became active, sometime in the early Pleistocene epoch.Harris, Tuttle, and Tuttle, p. 530.
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The first eruptive period produced a tuff ring and a long basaltic andesite lava flow about 100,000 years ago following a period of glacial retreat. Strombolian eruptions during the second and final eruptive period about 10,000 years ago constructed a small pyroclastic cone on the eastern rim of the older basaltic andesite tuff ring. A long lava flow, ranging from basalt to mugearite, issued from the base of the cone and travelled in a north-trending U-shaped valley on the eastern flank of The Black Tusk. Cinder Cone The Monmouth Creek complex on the west side of the Squamish River mouth is a prominent and enigmatic edifice composed of basaltic andesite and dacite of unknown age.
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The hanging wall to the deposit can be volcanic units essentially contiguous and coeval with the footwall rocks, indicating mineralisation was developed in an inter-eruptive pause; it may be volcanic rock dissimilar to the footwall volcanics in bimodal volcanic subtypes, or it could be sedimentary strata if mineralisation occurred toward the end of an eruptive cycle. Hybrid VMS-SEDEX deposits of the siliciclastic associations (see below) may be developed within interflow sediments or within units of sedimentary rocks which are present discontinuously throughout a larger and essentially contiguous volcanic package. Altogether, these geological features have been interpreted to show an association of VMS deposits with hydrothermal systems developed above or around submarine volcanic centres.
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Preston Cloud was the first scientist to systematically recognise the importance of the rich fossils of the Cambrian rocks in evolutionary terms. In order to explain the somewhat sudden appearance of diverse animals during the Cambrian Period, he invented the term "eruptive radiation" in his 1948 paper. According to him, the earlier use of the term like "explosive" was misleading because the actual evolution could occur over a period of millions of years, and it "probably did not make a loud noise," he described, as implicated by the term. He postulated that adaptive radiation in any favourable ecological condition could always result in diversification of an original population into several distinct lineages, thus giving rise to eruptive evolution.
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Chato Aislado is a volcano in Chile. Chato Aislado is part of the High Andes of Chile, between 25° and 26°30′ degrees south. The Andes there at altitudes over feature a number of volcanoes, as well as products of eruptive activity. The Salar Grande lies east of Chato Aislado.
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Zacualpan de Amilpas is in the foothills of the Popocatépetl Volcano; among the hills, there are deep, boxy ravines. The soils are a volcanic eruptive type. There are several streams including Amatzinac River, which has its source in the vicinity of the Popocatepetl volcano. Five streams are located in Tlacotepec.
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Eruptive pseudoangiomatosis is a cutaneous condition characterized by the sudden appearance of 2- to 4-mm blanchable red papules. It can appear in children or adults. The papules appear similar to hemangiomas (hence the name). Viruses found in patients include Echovirus 25 and 32, coxsackie B, Epstein-Barr virus, and cytomegalovirus.
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The last eruption consisted of smoking reported at the time of the 1877 Iquique earthquake. The volcano is currently considered dormant and there are no known fumaroles. Future eruptive activity may cause sector collapses, although they would be a small danger to human life, given that the area is sparsely inhabited.
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The first public performance in England was given by Sir Thomas Beecham in 1938. The tone poem itself provides a profound, yet cryptic glimpse of an elegiac, poetic world: an initial, harp- led stillness and reflection are succeeded by elemental, eruptive surges and, finally, a sense of renunciation or maybe death.
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Anatahan began erupting suddenly from its east crater on May 10, 2003, at about 6 p.m. (0800 UTC). It has since alternated between eruptive and calm periods. On April 6, 2005, approximately of ash and rock were ejected, causing a large, black cloud to drift south over Saipan and Tinian.
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Source Hill is a cinder cone in northwestern British Columbia, Canada. It is polygenetic in nature, having erupted more than once throughout its eruptive history.Catalogue of Canadian volcanoes: Source Hill It is one of the volcanoes in the central portion of the Mount Edziza volcanic complex and last erupted during the Pleistocene period.
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G. Moreau, C.J. Lucarotti (2007). A brief review of the past use of baculoviruses for the management of eruptive forest defoliators and recent developments on a sawfly virus in Canada. The Forestry Chronicle 83: 105-112. which has been shown to be involved in the natural decline of balsam fir sawfly outbreaks.
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Often, when a volcano explodes, biological organisms are killed and their remains are buried within the tephra layer. These fossils are later dated by scientists to determine the age of the fossil and its place within the fossil record. A 2007 eruptive plume at Mount Etna produced volcanic ash, pumice, and lava bombs.
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Explosive eruptions during this stage of activity deposited basalt agglomerates, ash fall and ash flow tuffs. Peralkaline felsic lava flows reached long and thick. The eruptive products of the bimodal stratovolcano stage cover an area roughly long and wide. Peralkalinity had remarkable effects on lava morphology and mineralogy during the bimodal stratovolcano stage.
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These include Aguas Calientes, Cerro Panizos, Galan and La Pacana. The area was also affected by stratovolcanoes and other styles of eruptive activity. These were often more diverse in chemical composition than the ignimbrite forming eruptions, a property attributed to various magma processes and the interaction between the mantle and the crust.
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Arenal is the youngest and most active of all the volcanoes in Costa Rica. Scientists have been able to date its activity back to more than 7000 years ago. The area remained largely unexplored until 1937, when a documented expedition took place to reach the summit. It has been considered eruptive since 1968.
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With the exception of some andesitic products, mostly lava flows, dacite is the main component of Panizos eruptive products. The rock matrix and clasts in the rock have similar minerals. Plagioclase is the main component of the lower cooling unit. Vesicles are rare in the Panizos ignimbrite, forming no more than 25%.
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Eruptive products consisted of scoria, black volcanic ash, and lapilli, with lapillisized scoria dominating. Scoria from the eruption had a coarse texture. Possibly the most recent eruption in the Santiam and McKenzie Passes region, this event formed an elongated crater with steep walls but a low rim. There were no lava flows.
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Its eruptive characteristics included central vent and explosive eruptions, pyroclastic flows, tsunamis and caldera collapse. This eruption had an effect on global climate. Volcanic activity ceased on 15 July 1815. Activity resumed in August 1819—a small eruption with "flames" and rumbling aftershocks, and was considered to be part of the 1815 eruption.
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The United States Geological Survey (USGS) has adopted a common system nationwide for characterizing the level of unrest and eruptive activity at volcanoes. The new volcano alert-level system classifies volcanoes now as being in a normal, advisory, watch or warning stage. Additionally, colors are used to denote the amount of ash produced.
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Historical eruptions of Hayes Volcano are not known and evidence of recent eruptive activity is not apparent on the volcano. During trips to the volcano in 1999 and 2000, signs of volcanic unrest, such as melting of glacier ice, steaming, or discoloration of the ice surface by volcanic ash were not observed.
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Fan and Mortar Geysers are two geysers in the Upper Geyser Basin in Yellowstone National Park. For the past several decades, they have erupted in concert with one another and are generally talked about together. The records detailing these geysers' known eruptive history shows that they have been infrequent and irregular performers.
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Bulletin of Volcanology. 33:566–578 aphyric basalt, olivine basalt and a third basalt which contains large phenocrysts of olivine, augite and plagioclase. These different rock types provide evidence for different eruptive phases. Kone is unusual due to the number of calderas in the Volcanic Complex, Fentale contains only one calderas in comparison.
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The slowdown in the eruptive activity was also evident from the decrease in intensity of crater glow and the diminishing volume of lava extruded from the summit. PHILVOLCS Alert Level 4 was lowered to Level 3 on September 11, 2006; to Level 2 on October 3, 2006; and to Level 1 on October 25, 2006.
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Volcanologists frequently visit volcanoes, especially active ones, to observe volcanic eruptions, collect eruptive products including tephra (such as ash or pumice), rock and lava samples. One major focus of inquiry is the prediction of eruptions; there is currently no accurate way to do this, but predicting eruptions could alleviate the impact on surrounding populations.
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The soil is volcanic and very rich in minerals. It is formed by the disintegration of one or several types of lava of different ages and eruptive materials such as lava, ash and sand. Containing all these particles, the crops cultivated on Etna soil benefit from nutrients like iron, copper, phosphorus, magnesium and others.
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Sarik-Gajah are two pyroclastic cones right at the equator line on Sumatra island, Indonesia. The first cone is Sarik, an andesitic/basaltic vegetated cone. The other is andesic-dacitic Gajah cone, 10 km south-west of the first one and it contains lava flow. No eruptive history ever recorded from this volcanic complex.
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Morne Plat Pays is a volcano on the island of Dominica. Located on the southern region of the island, the volcano last erupted around the year 1270 AD. Since the mid-18th century, a number of earthquake swarms have occurred near the mountain, but these are not related to Morne Plat Pays' eruptive activity.
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The stony rise flows have been dated at 300,000 years. Overlying the lava disc is a thin layer of tuff. The main hills and cones were built from scoria eruptions which succeeded the phreatomagmatic stage after groundwater had been depleted. Small lava flows from some vents beneath the scoria are the last eruptive activity.
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Mountains and hills can be characterized in several ways. Some mountains are volcanoes and can be characterized by the type of lava and eruptive history. Other mountains are shaped by glacial processes and can be characterized by their shape. Finally, many mountains can be characterized by the type of rock that make up their composition.
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The cancellation of 900 out of 90,000 European flights in the period 23–25 May was much less widespread than the 2010 disruption after the Eyjafjallajökull eruption. The eruption stopped at 02:40 UTC on 25 May 2011, although there was some explosive activity from the eruptive vents affecting only the area around the crater.
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Volcanologists frequently visit volcanoes, especially active ones, to observe volcanic eruptions, collect eruptive products including tephra (such as ash or pumice), rock and lava samples. One major focus of enquiry is the prediction of eruptions; there is currently no accurate way to do this, but predicting eruptions, like predicting earthquakes, could save many lives.
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Actually, there was considerable eruptive activity in the two weeks prior to the fatal blast, but since the phenomenon of the pyroclastic flow () was not yet understood, the danger was perceived to be from lava flows, which, it was believed, would be stopped by two valleys between the volcano and the city. Saint-Pierre.
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Because of the field's proximity to densely populated areas, eruptive activity would be a threat to human life, but the probability for future eruptions in the Portland–Vancouver metropolitan area is very low. Boring Lava may also influence future earthquakes in the area, as intrusive rock from its historic eruptions may affect ground movement.
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Three Fingered Jack shows a similar eruptive history to many High Cascade volcanoes. Activity began with the formation of a pyroclastic cone over shield volcanoes. Later eruptions formed a main volcanic cone from lava flows and more pyroclastic rock. There are dikes that radiate from a micronorite plug, which deformed tephra in the surrounding strata.
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A submarine eruption was reported in 1999 near the Kolbeinsey Ridge northwest of Grímsey. Kolbeinsey is the only subaerial expression of this portion of the Mid-Atlantic Ridge. It formed during the late-Pleistocene or Holocene. Dredged glass shards indicate submarine eruptive activity during the late-Pleistocene until at least 11,800 radiocarbon years ago.
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An Orion variable is a variable star which exhibits irregular and eruptive variations in its luminosity and is typically associated with diffuse nebulae. It is thought that these are young stars which will later become regular, non- variable stars on the zero-age main sequence. Brightness fluctuations can be as much as several magnitudes.
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Scientist collecting pahoehoe on the south side of Alae Crater subsidence bowl. Photo by R.L. Christiansen, February 12, 1972. Sampling gases at a fumarole on top of Mount Baker, Washington. A volcanologist or vulcanologist is a geologist who studies the processes involved in the formation and eruptive activity of volcanoes and their current and historic eruptions, known as volcanology.
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A. Gomes (2013) The second eruption, which started on 19 October 1652, resulted in the formation of three Trachyte domes and involved explosive phases of Vulcanian eruptions, by the time the eruptions end on 26 October 1652. This, more recent eruption, was a markedly eruptive/explosive event, composed of evolved magma that generally does not characterize the Picos region.
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Aerial view of Mount Villarrica The volcano resumed eruptive activity on March 8, 1963.Petit-Breuilh 2004, p. 230. On March 12 a flank vent some 250 metres below the summit begun to pour lava that ended up making a 1000 m long and 150-meter broad lava flow. The lava flow had stopped by March 19.
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During this period of non-eruptive seismic activity, it has been puffing steam, with puffs also occurring about every 1–2 minutes. There were reports in 2004 of small quantities of ash being emitted with the steam. A new period of activity started July 2019 with incandescence observed in the summit crater during a time of increased seismic activity.
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The remains of this violent origin can be seen in the basalt of the surrounding hills. The last eruptive phase ended some ten million years ago, leaving the prominent peak of Mount Cargill. Timaru was constructed on rolling hills created from the lava flows of the extinct Mount Horrible, which last erupted many thousands of years ago.
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Black Buttes is an extinct volcano with an amphitheater shape. It consists of jagged peaks that form an arc-shaped ridge, which were shaped and altered by glacial motion and erosion. Part of its amphitheater and its main eruptive crater is currently taken up by Deming Glacier, the rest of the volcano sitting above the glacier.
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Tin Taralle volcanic field is a volcanic field in the Aïr region of Niger, which covers a surface area of . It was active during the Pleistocene, with eruptive episodes between 28-20, 15-8 and 4 to 0.7 million years ago. The field consists of cinder cones which have mostly erupted basalt but also phonolite and trachyte.
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The centre of the volcano is Lou Island. Lou island last erupted in 240 BC (give or take 100 years) and 340 AD, both eruptions came from the Bendal volcano. Lou island is the largest eruptive centre of the volcano, with 6 volcanic vents. Also the Pam islands (Pam Lin and Pam Mandian) also contain fresh deposits.
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Also included here are several new melodic phrases. Piekut concluded that "Erk Gah" "holds little converse with rock convention. It sounds more like modernist chamber music scored mainly for amplified instruments". He added that "[t]here is very little repetition and no single drumbeat to speak of", although there are some "eruptive squeals" that are suggestive of free jazz.
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Multiple studies have provided evidence that there is no gender difference. However, a study by Kathmandu University reports that post eruptive breakdown occurs more frequently in boys than it does in girls. A different study found that children under the age of 10 are more highly affected by the disease (15.1%) compared to older children (12.1%).
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The shield stage of the volcano is subdivided into three phases: the submarine, explosive, and subaerial. During this stage of growth, the volcano accumulates about 95 percent of its mass and it takes on the "shield" shape that shield volcanoes are named for. It is also the stage at which the volcano's eruptive frequency reaches its peak.
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A comprehensive set of maps is included with the study, clearly showing the most likely affected areas in Boquete, Volcán, Bambito and other towns in vicinity of the Volcán Barú. The study recommends local authorities should make the population aware of the potential risks, and create a response system in preparation for the eventual onset of an eruptive episode.
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However, on 25 January Fanny fell ill. The attending doctor diagnosed the early stages of an eruptive fever and agreed with Kent that their lodgings were inadequate for someone at so critical a stage of pregnancy. Fanny was therefore moved, by coach, to Bartlet's Court. The next day her doctor returned and met with her apothecary.
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Eruptive activity commenced during the Pleistocene and continued during the Holocene. There is evidence of glaciation on the volcanoes, including moraines. The only historical activity of unspecified character occurred during 1865–1867; the volcano may still be a threat to Bolivia and Chile. It also features vigorous fumarolic activity and has been inspected for its geothermal energy potential.
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The lava domes were later destroyed after a sequence of strong eruptions that were part of an explosive eruptive cycle. These last eruptions were likely of phreatomagmatic and sub-plinian type and occurred around 1,100 years ago (~850 CE).Singer, Brad S., Jicha, Brian R., Harper. Melissa A., Naranjo, José A., Lara, Luis E., Moreno-Roa, Hugo.
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The whole mountain has been completely eroded by glaciers to an elevation of twice during its lifetime. The current cone was built during the most recent major eruptive period 40,000–10,000 years ago. Standing at , Adams towers about over the surrounding countryside. It is the second-highest mountain in Washington and third-highest in the Cascade Range.
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These end at adjacent ice-marginal lava flows that form cliffs. This eruptive phase also produced a lava dome that comprises the current high pinnacle. Consequently, the regional Late Pleistocene ice sheet carved a deep north- trending U-shaped valley into the eastern flank of the second-stage cone. Here, subsequent lava flows from Cinder Cone filled the valley.
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Particle of volcanic ash from Mount St. Helens. Volcanic ash particles erupted during magmatic eruptions are made up of various fractions of vitric (glassy, non-crystalline), crystalline or lithic (non-magmatic) particles. Ash produced during low viscosity magmatic eruptions (e.g., Hawaiian and Strombolian basaltic eruptions) produce a range of different pyroclasts dependent on the eruptive process.
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The eruption went through several stages, with six distinct marker horizons identified. Despite the uniform composition of the erupted magma, a wide variety of eruptive styles were displayed, including weak phreatomagmatism, Plinian eruptions, and a huge pyroclastic flow. Rhyolitic lava domes were extruded some years or decades later, forming the Horomatangi reefs and Waitahanui bank.Houghton, B.F. (2007).
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The volume of lava ejected during this single event is roughly equal to that ejected during the rest of the eruptive history at Quizapu, since its formation in 1846. Although of material was ejected, no subsidence was detected from the removal of magma.Hildreth and Drake, pp.96–98 Because of aerodynamic drag, a Plinian eruption excavates a circular crater.
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The Guacha system was constructed over a timespan of 2 million years with a total volume of . Eruptive activity occurred at regular intervals. Calculations indicate that the Guacha system was supplied by magmas at a rate of . Located at a high altitude in an area of long term arid climate has preserved old volcanic deposits over time.
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The volcano dates from the Mid-Holocene, is - following B. Hróarsson - about 6 000 years old, slightly younger than the Selvogsheiði, another shield volcano on Reykjanes peninsula, whereas Sinton defines its age as “finiglacial”, which would mean from the beginning of Holocene. J. Sinton, etal.: Postglacial eruptive history of the Western Volcanic Zone, Iceland. In: Geochemistry, geophysics, geosystems.
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Evidence indicates that in the beginning the Farallon Negro volcano grew rapidly, at least in the northwest sector and then growth petered out. Towards the end of activity around 7.3 mya a caldera collapse may have occurred. Composition of the eruptive products changed over the lifespan of the system. The main volcanism (9.2–6.8 mya) was andesitic-dacitic.
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Volcanology (also spelled vulcanology) is the study of volcanoes, lava, magma and related geological, geophysical and geochemical phenomena (volcanism). The term volcanology is derived from the Latin word vulcan. Vulcan was the ancient Roman god of fire. A volcanologist is a geologist who studies the eruptive activity and formation of volcanoes and their current and historic eruptions.
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By 4:00 a.m., lava fountains extended across the northeast half of Moku‘āweoweo and into the upper reaches of the northeast rift zone (flow B on map). At 10:30 a.m., intense steam emissions began along a fracture long farther down the northeast rift zone between the elevation, but no eruptive fissure formed in this area.
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Footage of Etna's November 2013 eruption. A large lava flow from an eruption in 1928 led to the destruction of a population centre for the first time since the 1669 eruption. The eruption started high on Etna's northeast flank on 2 November. Then new eruptive fissures opened at decreasing elevations down the flank of the volcano.
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There is no recorded eruptive activity, but the volcano displays vigorous fumarolic activity. It is located on top of older volcanic rocks and features both andesite and dacite. Lastarria has produced a large landslide deposit as well as flows of molten sulfur. A progressive uplift of the terrain around Lastarria and farther south has been recognized.
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Leilani Estates is located directly on a stretch of the lower East Rift Zone of Kīlauea volcano, in lava flow hazard zone 1. Zone 1 includes the summit and rift zones of active volcanoes--new eruptive vents can spawn anywhere inside this zone. Approximately 10% or out of the of Puna have been covered by lava flows since 1790.
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This indicates that an eruption is near. Sawmill drains after its eruptions, and if it had a large eruption prior, unusual behavior can occur in other geysers in the area. Sawmill was a frequent eruptor in recent years prior to January or February 2017, when it suddenly ceased eruptive activity. According to reports submitted to GeyserTimes.
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Risco Plateado is a stratovolcano in Argentina, with an elevation of above sea level. With a prominence of , it is one of the many ultra prominent peaks in the Andes. The equilibrium line altitude of the volcano lies at an altitude of . This stratovolcano has a wide caldera with eruptive centres on its northeastern and southwestern margins.
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Activity began during the Miocene; a younger eruptive stage, at the SE end of the volcanic field, occurred during the late-Pleistocene and Holocene.H. Stewart Edgell, Arabian Deserts: Nature, Origin and Evolution (Springer Science & Business Media, 21Jul.,2006 ) p329-330 It is known to have erupted in historic times.Peter Vincent, Saudi Arabia: An Environmental Overview (CRC Press, 2008) p22.
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Tephra layers in ice cores drilled at Byrd Station have been attributed to Mount Takahe. The volcano reaches an altitude high enough that tephras erupted from it can readily penetrate the tropopause and spread over Antarctica through the stratosphere. The occurrence of several volcanic eruptions in the region about 30,000years ago has been suggested to have caused a cooling of the climate of Antarctica, but it is also possible that the growth of the ice sheets at that time squeezed magma chambers at Mount Takahe and thus induced an increase of the eruptive activity. Assuming that most tephra layers at Byrd come from Mount Takahe, it has been inferred that the volcano was very active between 60,000 and 7,500 years ago, with nine eruptive periods and two pulses between 60,000–57,000and 40,000–14,000years ago.
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The Bulletin of Volcanology is a peer reviewed scientific journal that is published ten times per year by Springer Science+Business Media. It is the official journal of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI). The focus of the journal is volcanoes, volcanic products, eruptive behavior, and volcanic hazards. The Executive Editor is James DL White.
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On the morning of August 16, 2006, the Tungurahua volcano exploded, in what appears to be the main event of an eruptive process that started in 1999. On August 17, the whole of Pelileo woke up covered with rocks and ashes. In all the parishes of the county it is reported that crops have been lost and farm animals are in danger.
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On December 12, a short-lived explosion from Shishaldin expelled an ash cloud to 20-25,000 ft. During late December, eruptive activity continued with lava flows and low- level explosive activity at the summit. On January 3, 2020, seismicity led to an ash cloud eruption which reached as high as 27,000 feet. Another large ash cloud was emitted January 19 2020.
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The system developed for Stromboli has ensured seismic monitoring during the eruptive crises of 2002–2003 and 2007 by providing a large amount of data processed daily. Thanks to its advanced design and the development of new automatic analysis systems, it allows us to obtain in real-time the maximum information from the acquired data and to highlight its significance.
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At least three volcanic centres (Guacha caldera, La Pacana, Pastos Grandes, Vilama) had eruptions of a Volcanic Exposivity Index (VEI) of 8, as well as smaller scale eruptive centres. Activity waned after 2 mya, but present-day geothermal activity and volcanoes dated to the Holocene, as well as recent ground deformation at Uturunku volcano indicate still-extant present-day activity of the system.
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While remote sensing is able to collect data of ground, 3-D modeling using finite element analysis added with geophysical subsurface survey is highly encouraged.An ASTER night time thermal infrared image capturing 2015 eruption of Calbuco Volcano in Chile. Hot eruptive material at the summit appears in white (hot), with a purple plume streaming to the right, indicating that it is ash-laden.
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The last volcano to erupt was much bigger than all others, with Rangitoto making up 41 per cent of the field's entire volume of erupted material. Kereszturi, G., Németh, K., Cronin, S. J., Agustín-Flores, J., Smith, I. E., & Lindsay, J. (2013). A model for calculating eruptive volumes for monogenetic volcanoes—Implication for the Quaternary Auckland Volcanic Field, New Zealand.
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Gabbroic clots embedded in the lavas probably formed from cumulates. Xenocrysts with large reaction rims testify to a strong crustal contamination of the forming magma. The overall magma temperatures ranged for the andesitic and dacitic magmas and in the basaltic andesite. The magmas became cooler over time, with the post-collapse magmas being colder than the pre-collapse eruptive products.
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General view of the puy de Pariou from the south-west The Puy de Pariou, also known as Puy Pariou or Le Pariou, is a volcano located in the Chaîne des Puys, in the Massif Central region. It is formed by the overlay of two strombolian cones and a tuff ring; it produced three lava flows during its eruptive history.
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The eruption had a VEI of 4. Parícutin and El Jorullo both rose in an area known for its volcanoes. Called the Trans-Mexican Volcanic Belt, the region stretches about 700 miles (1,120 km) from east to west across southern Mexico. The eruptive activity deposited a layer of volcanic rock some 6,000 feet thick, creating a high and fertile plateau.
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Meszah Peak is a volcanic cone located north of Telegraph Creek and southwest of Zus Mountain in British Columbia, Canada. It is the highest peak of the Level Mountain Range, a cluster of bare peaks on the summit of the massive Level Mountain shield volcano, which forms the most voluminous and most persistent eruptive centre in the Northern Cordilleran Volcanic Province.
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The graph of eruption rate shows plunges which indicate lessening in diffusive activity or cooling of old flow surface. As well, it shows a spike, which indicates the beginning of a new eruption. The power output flux graph compares Zamama with other Ionian volcanoes of the same eruptive style. Galileo NIMS instrument collected data on volcanic emissions to analyze the power output.
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Mount Akutan, officially Akutan Peak, is a stratovolcano in the Aleutian Islands of Alaska. Akutan Peak, at , is the highest point on the caldera of the Akutan stratovolcano. Akutan contains a 2 km-wide caldera formed during a major explosive eruption about 1600 years ago. Recent eruptive activity has originated from a large cinder cone on the NE part of the caldera.
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Eruptive centres gradually migrated southward, where they transitioned into early activity in the Taupo Volcanic Zone. Later activity in the CVZ is obscured by subsequent events and is not fully understood, but continued in the south until around 1.9 million years ago. Together with the extinct undersea Colville Ridge, the CVZ formed a precursor to the modern Taupo Volcanic Zone and Kermadec Ridge.
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By 1932, Quizapu had produced many phreatic events and one effusive eruption, but no large Plinian eruptions. This frequency of minor eruptive activity proved to be a precursor for a major eruption. On 25 January 1932, observers in Malargue saw a large black cloud over the summit. By 9 April, the volcano emitted green gas and started to "bellow like a bull".
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At 4 PM, coarser sandy material and some pumice lapilli began to fall. Cerro Azul's April 1932 eruption was one of the largest of the 20th century. Releasing of lava, the volcano ejected primarily dacitic tephra, accompanied by rhyodacite, andesite, and minuscule amounts of andesitic and basaltic scoria. At least one eruptive period lasted for 18 hours, creating an "exceptionally uniform" deposit.
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The first eruptive phase started about four million years ago with the eruption of dacite lava flows and pyroclastic rock. This resulted in the creation of the Mount Cayley proper. Subsequent volcanism during this volcanic phase constructed a significant lava dome. This acts like a volcanic plug and composes the lava spines that currently form pinnacles on Cayley's rugged summit.
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The Yn tephra is a geologically recent tephra deposit that covers portions of the U.S. state of Washington and the Canadian provinces of British Columbia and Alberta. It was created by the largest known volcanic eruption from Mount St. Helens, having taken place in possibly 1860 BCE as part of the Smith Creek eruptive period. The tephra consists of pumiceous dacite.
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The harbour was formed from the drowned remnants of the giant Dunedin Volcano, centred close to what is now Port Chalmers. The remains of this violent origin can be seen in the basalt of the surrounding hills. The last eruptive phase ended some ten million years ago, leaving the prominent peak of Mount Cargill.Coombs, D. S., Dunedin Volcano, Misc. Publ.
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A series of sub-plinian events then occurred from January 19th to the 31st (Brothelande E., et al, 2018). The first phase (eruption climax) was accompanied by a strong co-eruptive deflation. Aira Caldera may respond to small eruptions that come from a common reservoir. However, not all the volcanic systems are connected all the time as magma pathways open and close.
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The eruption under Eyjafjallajökull ("glacier of Eyjafjöll") in April 2010 was notable for causing enormous disruption to air travel across western and northern Europe over a period of six days in April 2010. About 20 countries closed their airspace to commercial jet traffic and it affected approximately 10 million travellers. However this volcano is minor in Icelandic terms (VEI4)Eyjafjallajökull. Eruptive History.
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Nearly all of these eruptions were confined to single vents or small vent complexes, with the exception of a lava plain southeast of present-day Oregon City. Boring Lava generally consists of flowing lava; only one eruptive deposit contains tuff, ash, and tuff breccia, and one vent to the northeast of the Carver area displayed evidence of explosive eruptions that later became effusive.
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Because of its distance from the trench, its eruptive fluids are hotter (over ), less alkalic, and with more calcium. Its flows have a pH of 12.2 (highly basic) and are sulfate and methane rich. Serpentine mud volcanoes are currently limited to the Izu-Bonin-Mariana arc; however, there is evidence of the geological remnants of similar volcanics globally, throughout Earth's history.
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Since "supervolcano" calderas can have eruptive lifespans sometimes measured in millions of years, a caldera that has not produced an eruption in tens of thousands of years is likely to be considered dormant instead of extinct. Some volcanologists refer to extinct volcanoes as inactive, though the term is now more commonly used for dormant volcanoes once thought to be extinct.
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Water from this lake feeds Butte Lake, located to the north. Butte Lake is the sole remaining fragment of a much larger body of water filled with lava during Cinder Cone's eruptive period. Diatomite sediment, formed from the aggregation of diatoms on the lake's floor, run along the edges of the Fantastic Lava Beds and mark the margins of this former lake.
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Erosion has been so extensive that climbers claim that the summit moves in the wind. During the Pleistocene epoch, glaciers exposed its inner contents, providing evidence for its eruptive history. Though it has not been dated by radiometric approaches, the volcano is likely between 500,000 and 250,000 years old, and has been carved out by at least three glacial periods.
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According to NASA, the origin of lunar sinuous rilles remains controversial. The Hadley Rille is a 1.5 km wide and over 300 m deep sinuous rille. It is thought to be a giant conduit that carried lava from an eruptive vent far to the south. Topographic information obtained from the Apollo 15 photographs supports this possibility; however, many puzzles about the rille remain.
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Others, such as Cave Basalt (known for its system of lava tubes), flowed up to from their vents. During the first century, mudflows moved down the Toutle and Kalama river valleys and may have reached the Columbia River. Another 400 years of dormancy ensued. The Sugar Bowl eruptive period was short and markedly different from other periods in Mount St. Helens history.
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This stage generated a sustained eruption column about high, which likely also created a mushroom cloud. The eruption cloud darkened the sky, obscuring the sun and the stars. Afterwards, collapses in the amphitheatre and within the vent enlarged both features and impeded further eruptive activity. A first pyroclastic flow was emplaced already during this time when the column became unstable.
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Tajumulco is composed of andesitic-dacitic lavas on the top of a large escarpment of uncertain origin. It has two summits, one of which has a crater wide. A lava flow from the north-western summit descends into a steep valley on the same side of the volcano. The volcano's eruptive history is unclear and the date of its last eruption is unknown.
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The lavas formed have been plagioclase ultraphyric basalts with large 4 cm crystals. This chemical makeup is similar to those found in lavas from the northern Galápagos Islands. The extent of the ultraphyric flows make up an unusually large percentage of the volume. There is large variation in the composition of the lavas between eruptive phases, with later flows being depleted.
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It is an eruptive variable of the T Tauri type with an estimated age of 2.4 million years. The object has 76% of the mass of the Sun, 181% of the Sun's radius, and is spinning with a projected rotational velocity of 13 km/s. AA Tauri is radiating 80% of the luminosity of the Sun at an effective temperature of 4,060 K.
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The youngest unit is latitic and was dated 0.1 ± (0.1-0.3) mya ago. This unit may be Holocene or PleistoceneHolocene in age. It is possible that the continuing activity of the Chorrillos fault zone is compressing the magma chamber and feeder dyke of Tuzgle, thus impeding eruptive activity. The well- preserved summit crater and youthful-looking lava flows have been assigned Holocene ages.
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Afterwards, lava flows were generated. The Igwisi Hills are the only places in the world where possible kimberlite lava flows have been found, in form of calcite-olivine lavas. Kimberlite tuffs are also found, a rare species which is very susceptible to erosion. True kimberlites are usually very old eruptive rocks, consequently any subsurface volcanic structure has long since been eroded away.
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Prediction of sunspot cycle Many solar phenomena change periodically over an average interval of about 11 years. This solar cycle affects solar irradiation and influences space weather, terrestrial weather and climate. The solar cycle also modulates the flux of short-wavelength solar radiation, from ultraviolet to X-ray and influences the frequency of solar flares, coronal mass ejections and other solar eruptive phenomena.
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In October 2006, the United States Geological Survey (USGS) adopted a nationwide alert system for characterizing the level of unrest and eruptive activity at volcanoes. The system is now used by the Alaska Volcano Observatory, the California Volcano Observatory (California and Nevada), the Cascades Volcano Observatory (Washington, Oregon and Idaho), the Hawaiian Volcano Observatory and the Yellowstone Volcano Observatory (Montana, Wyoming, Colorado, Utah, New Mexico and Arizona). Under this system, the USGS ranks the level of activity at a U.S. volcano using the terms "normal", for typical volcanic activity in a non-eruptive phase; "advisory", for elevated unrest; "watch", for escalating unrest or an eruption underway that poses limited hazards; and, "warning", if a highly hazardous eruption is underway or imminent. These levels reflect conditions at a volcano and the expected or ongoing hazardous volcanic phenomena.
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This, combined with the abrupt occurrence of most human differentiations in that same period, is a probable case of bottleneck linked to volcanic winters (see Toba catastrophe theory). On average, super-eruptions with total eruptive masses of at least 1015 kg (Toba eruptive mass = 6.9 × 1015 kg) occur every 1 million years. However, archaeologists who in 2013 found a microscopic layer of glassy volcanic ash in sediments of Lake Malawi, and definitively linked the ash to the 75,000-year- old Toba super-eruption, went on to note a complete absence of the change in fossil type close to the ash layer that would be expected following a severe volcanic winter. This result led the archaeologists to conclude that the largest known volcanic eruption in the history of the human species did not significantly alter the climate of East Africa.
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This date is similar to that of the oldest dated extant lava flow, a southwestern rift zone flow with an uncorrected radiocarbon dating of approximately 4650 BC. The oldest well-studied eruptive product from Kīlauea is the Uwēkahuna Ash Member, the product of explosive eruptions between 2,800 and 2,100 years ago. Although it has since been largely buried by younger flows, it remains exposed in some places, and has been traced more than from the volcano's caldera, evidence of very powerful eruptions. Evidence suggests the existence of an active eruptive center at this time, termed the Powers Caldera, whose fractures and faults lie outside the modern caldera. At least 1,200 years ago, lava from the Powers Caldera overtopped its rim and solidified the structure; this was followed by a period of very voluminous tube-fed pāhoehoe flows from the summit.
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From 1993 onward, the rate of lava effusion gradually decreased, and eruptions came to an end in 1995. The 1990–1995 eruptions of Unzen were the first eruptive activities in the world where pyroclastic flows were recorded clearly and continuously on video (in the past, many pyroclastic flows, such as those on Mt. Pelee, were recorded either as photographs or on small-scale videos).
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The eruption did not affect the communities in the area but left a lot of ash and air pollution. Sulfate aerosols formed by volcanic sulfur dioxide from the eruptions were observed as far away as over the central Amazon rain forest in South America. By 2018, the lava lake had hardened and the activity appeared to have stopped. Eruptive activity continues during 2020 at the summit caldera.
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Any volcanic hazard—ranging from landslides to eruptions—could pose a significant risk to humans and wildlife. Even though there are no historical eruptions in the Canadian Cascade Arc, eruptive activity is very likely to resume; if this were to happen, relief efforts would be quickly organized. Teams such as the Interagency Volcanic Event Notification Plan (IVENP) are prepared to notify people threatened by volcanic eruptions.
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Prolonged erosion destroyed the original cone. The bluffs northwest, southwest and southeast of the main volcanic edifice are remains of this ancestral volcano. Renewed volcanism between 210,000 and 170,000 years ago produced hypersthene andesite lava flows, which locally terminate with precipitous thick ice-contact margins. This latest eruptive activity culminated with extrusion of an endogenous dome and related lava which form the present high summit spire.
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Guttate psoriasis (also known as eruptive psoriasis) is a type of psoriasis that presents as small (0.5–1.5 cm in diameter) lesions over the upper trunk and proximal extremities; it is found frequently in young adults. The term "guttate" is used to describe the drop-like appearance of skin lesions. Guttate psoriasis is classically triggered by a bacterial infection, usually an upper respiratory tract infection.
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The Eastern Volcanic Zone (EVZ) is located in south-east Iceland. It connects to the South Iceland Seismic Zone and NVC in its western and northern end respectively. Seismic activity focuses in the Vatnajökull Glacier area which is the accepted location of the Icelandic hot spot. Deformed structures, including northeast trending eruptive fissure swarms and normal faults, can be found in Eastern Volcanic Zone.
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This massive volcano complex towers more than 3,500 metres above the Pacific coastal plain to the south and 2,000 metres above the Guatemalan Highlands to the north. The volcano complex comprises remnants of multiple eruptive centres, which periodically have collapsed to form huge debris avalanches. The largest of these avalanches extended more than 50 kilometres from its source and covered more than 300 square kilometres.
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Because of the lack of opposing force and the natural eruptive potential of the tooth there is a tendency for the tooth to erupt out of the line of the occlusion. Not all teeth lacking an opposing tooth overerupt, even in long term. Unopposed upper jaw molars overerupt more than the unopposed lower jaw molars. It is more severe in young people and periodontically affected people.
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Scientists immediately installed monitoring equipment and analyzed the volcano for clues as to its previous eruptive history. Radiocarbon dating of charcoal found in old volcanic deposits revealed the last three major explosive eruption periods in recent millennia, about 5500, 3500 and 500 years ago. Geological mapping showed that much of the surrounding plains were formed by lahar flood deposits from previous eruptions. Volcanic activity increased throughout May.
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The first evidence of volcanic activity in this area dates back to 400,000 years ago, but the first major eruptive phenomenon of some significance occurred about 25,000 years ago: the eruption of the pumice base when the top of the Somma–Vesuvius volcano collapsed forming a caldera, in which was later formed Vesuvius. Today's Mount Somma is only the caldera on the northern side.
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Level Mountain has experienced volcanic eruptions sporadically for the last 15 million years, making it the most persistent volcano of the NCVP. More than 20 eruptive centres are present on the summit and flanks of the complex. These have produced mainly felsic and mafic lavas, a chemical composition range typical of bimodal volcanism. Such volcanism commonly occurs at hotspots, continental rifts and leaky transform faults.
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The group was first defined by Bailey, Smith, and Ross in 1969 as part of their work establishing the stratigraphy of the Jemez Mountains. The group was named for Polvadera Peak, which is a major eruptive center for the group and the second highest peak in the Jemez Mountains (). They included in the group the Lobato Basalt, the Tschicoma Formation, and the El Rechuelos Rhyolite.Smith et al.
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The magmatic material was olivine basalt from a mantle source. Pyroclastic surge from the eruptions traveled to the northwest. The volume of lava erupted was 9×105 m3 and the volume of tephra expelled was 2.6×107 m3.GVP Ukinrek Maars, Eruptive history The Quaternary age Gas Rocks dacite domes some three km to the northeast were the site of a phreatic eruption some 2300 years ago.
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Because of the prominence of the yacht's owner, Mr. P.A.B. Widener, Dr. Joseph Goldberger of the United States Public Health Service was sent to Philadelphia to work with Schamberg on ascertaining the cause of the eruption. Schamberg and Goldberger demonstrated that the eruption was caused by mites found in the straw of the crew members' bunks.Schamberg, Jay (1911). Diseases of the Skin and Eruptive Fevers.
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Lady Knox Geyser, in the Waiotapu geothermal area Mayor Island is a peralkaline shield volcano with a caldera partly formed in a large eruption some 7000 years ago. It has exhibited many eruptive styles, and its last eruption may have occurred only 500–1000 years ago. The island's Maori name, Tuhua, refers to the obsidian they found on the island and prized for its sharp cutting edge.
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The Kīlauea District, including the visitor center, reopened to the public on September 22, 2018. Eruptive activity, ground collapses and explosions in the park had ceased in early August. At the summit, seismicity and deformation are negligible. Sulfur dioxide emission rates at both the summit and the Lower East Rift Zone are drastically reduced; the combined rate is lower than at any time since late 2007.
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During this period, Cerro Azul sometimes erupted daily, sending columns of ash as far as 6 or 7 kilometers (about 4 mi) into the air. Quizapu Crater grew slightly during this eruptive period. Pre-1932 volcanism was largely phreatic or fumarolic, as evidenced by the lack of tephra generated by these eruptions. Photographs from 1912 show vapor plumes containing little ash, rising above the crater.
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Constructed from an elastomeric material, these preformed activators are used in the primary to adult dentition but ideal for use in the early through late mixed dentition. Along with their activator properties, ideal for correction of class II malocclusion, being based on tooth size, these appliances aptly coined EGAs (Eruptive Guidance Appliances) also function as a positioner along with correcting overbite and mild to moderate crowding.
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Fresh lava and pyroclastic flows imply recent activity, with two pyroclastic flows dated to 44,500 and 49,200 years before present. Sara Sara is currently classified as a dormant volcano. Future eruptive activity could generate lahars, lava flows, Plinian eruption deposits and pyroclastic flows. Aside from Pausa, other towns and Lake Parinacochas (an important source of water for the region) are located close to the volcano.
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Phase 3 was created by "phreatomagmatic fragmentation," in which clastic fragments are driven by superheated steam from ground water mixed with the other gases released from the magma. The authors characterize Phase 3 as "the most voluminous and widespread in the whole of Somma-Vesuvius's eruptive history." Some facies a few cm thick were found from the source. The vent was west of today's center.
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A seismograph, placed on the underwater island in 2006, is recovered in 2007 After 1863, the volcano lay dormant for many decades, its summit just below sea level. In 2000, renewed seismic activity around Graham Island led volcanologists to speculate that a new eruptive episode could be imminent, and the seamount might once again become an island."Bourbons surface to retake island". The Guardian.
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An eruptive prominence on the surface of the sun. The plasma is the most common state of the baryonic matter in the Universe (99%). Most of a star, the interplanetary and interstellar medium, and the ionosphere, are plasmas. The plasma can also be generated in terrestrial laboratories for industrial applications such as producing surface coatings, precision cuts in lamps, micro-motors, and plasma reactors.
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An intrusive rock, similar to dolerite, but with an excess of quartz. Dolerite is similar in composition to basalt, which is eruptive (from volcanoes), and gabbro, which is plutonic. The differing crystal sizes are due to the different rate of cooling, basalt cools quickly and has a very fine structure, while gabbro cools very slowly, at great depth, and large crystals develop. Dolerite is intermediate.
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The distance between individual volcanoes has shrunk. Although volcanoes have been drifting north faster and spending less time active, the far greater modern eruptive volume of the hotspot has generated more closely spaced volcanoes, and many of them overlap, forming such superstructures as Hawaii island and the ancient Maui Nui. Meanwhile, many of the volcanoes in the Emperor seamounts are separated by or even as much as .
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Snavely et al., recognizing at least 10,000 feet of thickness, and as much as 20,000 feet under eruptive centers, estimated the volume to be in excess of 50,000 cubic miles (over 200,000 km3).. estimated around 250,000 km3 (about 60,000 cubic miles), which exceeds the volume of most continental rift zones, and some flood basalt provinces.. A recent estimate put the volume at 2 million cubic km. (abstract).
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The Bella Bella and Gale Passage dike swarms are petrographically similar to the shield complexes in the central Anahim Volcanic Belt. As a result, the swarms are thought to represent the roots of a peralkaline magma system in which they are the magma conduits connecting the underlying magma chamber to the volcanic centre at the surface, which has been extensively eroded to remnants of eruptive breccia.
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Tuli Mons (13°N, 314.5°) is ~600x800 km across and contains a ~100x200 km field of low shields at its summit. Tuli rises an average of 600 m above its surroundings, and its flanks consist of a series of lobate, narrow flows which radiate from the summit region. Progressing north, large flow fields extend onto the plains and unite with a secondary eruptive center.
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A part of the Basin and Range Province, the volcano's most recent eruptive activity dates to approximately 15 million years ago (the Miocene), forming during a period of active volcanism including eruptions of ignimbrite and ash. It formed around the same time as Three Fingers, Castle Peak, and three other volcanoes. Today the volcano appears gnarled due to erosion and is topped by pine forests.Bishop, p. 158.
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Volcaniclastic sedimentary rocks are common in shallow-water environments. As plate movement starts to carry the volcanoes away from their eruptive source, eruption rates start to die down, and water erosion grinds the volcano down. The final stages of eruption cap the seamount in alkalic flows. There are about 100,000 deepwater volcanoes in the world, although most are beyond the active stage of their life.
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Northern pintail The mild winters make Britain attractive to about 60 species which breed further north. These are mainly larger birds, such as swans, geese, ducks, gulls and thrushes, but some smaller species, such as the snow bunting and brambling also arrive in large numbers. The numbers of some eruptive species, like Bohemian waxwing, depend on food supplies and population numbers in their breeding areas.
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The northern and southern flanks of Three Fingered Jack feature lava flows made of olivine and augite basalt. Three Fingered Jack is estimated to be between 500,000 and 250,000 years old. It underwent more explosive eruptions as its eruptive history progressed, generating large amounts of tephra, which created a loose, unconsolidated summit and upper cone. Lava flows near the summit have an average thickness of .
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Acatenango volcano. This massive volcano complex towers more than 3,500 metres above the Pacific coastal plain to the south and 2,000 metres above the Guatemalan Highlands to the north. The volcano complex comprises remnants of multiple eruptive centers, which periodically have collapsed to form huge debris avalanches. The largest of these avalanches extended more than 50 kilometres from its source and covered more than 300 square kilometres.
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The Puhinui Craters are located in Auckland's Puhinui Reserve and are part of the Auckland volcanic field in the North Island of New Zealand. They were first recognised as volcanic craters in 2011. A cluster of three small maar craters like these is unique in the Auckland volcanic field. Their ages are unknown but most probably all three erupted during the same eruptive episode.
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The Natural Resources Canada employees also measured carbon dioxide levels during the earthquake swarm. Carbon dioxide is usually discharged at faults in volcanically active areas and can collect in soil and under snow. Because of this, carbon dioxide concentrations can provide information on volcanic activity in the subsurface. The Nazko swarm did not cause any discernible discharge of carbon dioxide, which is normal for non-eruptive events.
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Their slopes are covered with their eruptive products and serve as the surface expressions of intrusions. As a result, they provide a unique opportunity to study the relationships between magma chambers and their lavas. The mafic (rich in magnesium and iron), intermediate (between mafic and felsic) and felsic (rich in feldspar and quartz) volcanic rocks of the massif were erupted from at least eight volcanic vents.
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Lava flows are subordinate. Luingo is the eruptive centre of the Pucarilla-Cerro Tipillas volcanic complex. Unlike other calderas such as Galan, Luingo is not visible from satellite images; its location and existence has been inferred from analysis of the facies and morphology. This caldera is the source of the Alto de Las Lagunas and Pucarilla ignimbrites and is itself filled by the two Luingo ignimbrites.
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During the Holocene epoch, volcanic activity has been particularly concentrated between the North Sister volcano and Three Fingered Jack, with at least 125 distinct eruptive centers active since the retreat of Pleistocene glaciers. Eruptive activity in the upper McKenzie River catchment has been taking place since after the eruption of Mount Mazama about 7,700 years ago. Thus, it represents one of the youngest volcanic regions in the Cascade Arc. This activity is concentrated in the central Oregon Cascades, at the northwestern margin of the High Cascades graben near the boundary of the High Cascades and Western Cascades. The last eruption in the Sand Mountain Volcanic Field took place about 2,000 years ago at the Lost Lake cinder cone group, which lies at the northern–northeastern end of the field. Before that, about 3,000 to 4,000 years ago, lava flows erupted from vents along the chain.
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The main origin of the sill may be in the region of the eruptive centre that formed the Ochil Hills in a much earlier period, which geologists postulate is somewhere to the east of Stirling, possibly in the region of Kincardine. This ties in with subsidence following the first round of eruptive activity that lead to the formation of the coal basins, with a much later outbreak of intrusive activity from the same magma feeders, however the truth will remain unknown because it would take very many deep bores in hard rock to probe the depths and find the necessary evidence. The western extremities of the sill can be seen at the Abbey Craig, Stirling Castle, Kings Park, Gillies Hill, Sauchieburn and various points to the south. The quartz-dolerite was once quarried at several places including Cambusbarron and Murrayshall, but is quarried today at Northfield, primarily for roadstone.
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In a paper published in 1976, he described the location of each group and the west-east-trending movement of volcanism in the range. To the west of the Chilean Andes are an early group of eruptions, dated from the Oligocene and the Early Miocene (33.3–20.2 mya). The scale of the eruptive events that produced these features remains unclear. Further east, in the actual range, are huge numbers of eruptions.
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2 (1999): 223. JSTOR Journals, EBSCOhost. In the time of Pinatubo’s eruptive phase in June 1991, most of the population reacted favorably to the evacuation orders due to the early preparation and coordination efforts the authorities on the field have demonstrated. However, there were still some Aetas that changed their minds and decided to return to the mountains seeking refuge in caves and spiritual comfort from their God.
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The volcano itself is constructed from lava domes and flows on top of Miocene ignimbrites. Several stages of eruptive activity are recognized, some of them exposed through erosion. A northwestern debris avalanche has been found on Isluga, on top of which the recent volcano is constructed. The fumarolically active crater region has been buried with surge deposits from phreatomagmatic activity, and the northern ridge is covered by Holocene lavas.
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Between 2004 and 2007, ground inflation began in the volcanic field, indicating the intrusion of a sill beneath it. The rate of inflation is faster than those measured on other inflating volcanoes such as Uturunku in Bolivia and Yellowstone Caldera in the United States and has been accompanied by anomalies in soil gas emission and seismic activity. This pattern has created concern about the potential for impending large-scale eruptive activity.
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It is wide, with steep slopes extending from near sea level to a maximum elevation of . Like Franklin to the south-southeast, Silverthrone has not been studied in detail by scientists. As a result, its affinity and eruptive history is poorly known. It is considered to be part of the Garibaldi Volcanic Belt, but it also lies on the overlapping trend of the much older Pemberton Volcanic Belt.
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The Ubehebe Craters are considered to be of Holocene age. They formed in a single episode about 2,100 years ago around 150 BCE. The timing of eruptive activity was determined with the help of archeomagnetic dating, beryllium-10 radiometric dating, and tephrochronology. This makes Ubehebe Craters the most recent basaltic eruption in the continental United States and, together with the Salton Buttes, one of the youngest in southern California.
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The volcano and its eruptive products are protected in Garibaldi Provincial Park. Founded in 1927 as a Class A provincial park, this wilderness park covers an area of . Lying within its boundaries are a number of other volcanoes, such as Mount Garibaldi and The Black Tusk. Located north of Vancouver in the glaciated Coast Mountains, Garibaldi Provincial Park contains diverse vegetation, iridescent waters and a rich geological history.
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The cysts are mostly small (2-20 mm) but they may be several centimetres in diameter. They tend to be soft to firm semi-translucent bumps, and contain an oily, yellow liquid. Sometimes a small central punctum can be identified and they may contain one or more hairs (eruptive vellus hair cysts). They may become inflamed and heal with scarring, like acne nodules (see nodulocystic acne and hidradenitis suppurativa).
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The setting up of these initial projections corresponds to the beginning of the eruption when magma rises to the surface in contact with continental water. It causes heavy explosions capable of breaking fragments of crystalline basement, and the appearance of volcanic bombs in cauliflower shapes. Thereafter, water is removed and activity becomes more magmatic than phreatic. After cessation of eruptive activity, the Gour de Tazenat gradually filled with rainwater.
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However, Kookoolau has pumice cones on the rim that suggest it formed originally as an eruptive vent. The road runs into Hilina Pali Road, a winding eight-mile road that dead ends. The road passes Pauahi crater, and fresh fault scarp that have been active for more than 1000 years. The road continues through a forest, Kipuka Nene, where 1,100-year-old trees are surrounded by fresh lava.
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1058 The first and the main volcanic phase of this volcanic province occurred in the Early Jurassic (late Sinemurian to Toarcian) at 191–178 Ma.Bergelin, 2009 Analysis of the volcanic rocks produced by this Jurassic volcanism suggests a continental Strombolian-type eruptive character close to the oceans of the Early Jurassic.Augustsson, 2009 No correlative pyroclastic beds have yet been identified in sedimentary basins surrounding central Skåne.Ahlberg et al., 2003, p.
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The species may be threatened, or even extinct, as only one specimen has ever been collected, some 70 years ago. In addition Tungurahua, the Ecuadorian volcano that served as the species' habitat, entered a new eruptive phase in 1999. The species was listed among the Top 10 New Species 2012 as selected by the International Institute for Species Exploration at Arizona State University out of more than 140 nominated species.
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Prevention is of prior importance at an early developmental age as the defective tooth is more likely to have caries and post-eruptive breakdown due to its increased porosity. Appropriate dietary advice and toothpaste with a fluoride level of at least 1,000 ppm F should be recommended. For treating spontaneous hypersensitivity professional applications of fluoride varnish (e.g. Duraphat 22,600ppm F) or 0.4% stannous fluoride gel may be helpful.
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Intra-plate basaltic volcanism has occurred in Northland from late Miocene to Quaternary times. The Kerikeri volcanic group covered the area from Kaikohe, Kerikeri, to Whangarei. Activity began about 9 Ma, and the youngest cones are probably only tens of thousands of years old. Little Barrier Island is the emergent part of a large dacitic-rhyodacitic stratovolcano, formed through two eruptive periods (3 Ma, and 1.6–1.2 Ma).
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Qal'eh Hasan Ali has been active during the Quaternary, the eruptions that formed the craters probably took place between 5,000 and 50,000 years ago. Potassium-argon dating on rocks from the Great Crater have indicated an age of 119,000–112,000 years ago. No has been detected in Pakistan that could be attributed to this field. The eruptive activity that generated the craters was probably non-explosive, with fountaining.
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There was also eruptive activity in 2009 involving minor phreatic eruptions and landslides within the northern active crater. Poás eruptions often include geyser-like ejections of crater-lake water. On February 25, 2014, a webcam from the Volcanological and Seismological Observatory of Costa Rica (OVSICORI) captured the moment a dark cloud exploded about 1,000 feet in the air from a massive crater of the Poás Volcano. This volcano remains active today.
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To the northwest, the Mount Cayley massif constitutes the largest and most persistent volcano in the central Garibaldi Belt. It is a highly eroded stratovolcano composed of dacite and rhyodacite lava that was deposited during three phases of volcanic activity. The first eruptive phase started about four million years ago with the eruption of dacite lava flows and pyroclastic rock. This resulted in the creation of Mount Cayley itself.
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1987 marked a milestone in Gareloi's eruptive history, when a flow, likely to be of volcanic origin, was observed by a commercial airplane pilot. The mass extended for down the volcano. Steam reportedly emanated from the volcano, but volcanologists were unable to verify an eruption. In 1989 an employee of the US Fish and Wildlife Service spotted another ash plume covering the caldera and climbing from the summit on August 17.
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Its largest historical eruption was at Quizapu Crater, located on the north side of Cerro Azul's summit (see below), and its most active volcanoes are Llaima and Villarrica.Stern et al., pp. 154–156. Cerro Azul, just south of Descabezado Grande volcano, is part of the Descabezado Grande–Cerro Azul eruptive system, a volcanic field that comprises its two large namesake volcanic edifices and several smaller vents, including 12 Holocene calderas.
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On November 26, 1846, Cerro Azul erupted. This was the first report of activity at the volcano, and no trace of fumaroles, adjacent vents, or pre-eruptive activity exists. Most descriptions of the eruption come from the backcountry herdsmen (arrieros). One, who was camped in a valley approximately east of Quizapu, heard "a great noise and a cloud of ash" emanate from the mountain in the late afternoon.
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Omicron Herculis is an eruptive variable of the Gamma Cassiopeiae class, which are rapidly rotating B-class stars with mass outflow. It has a projected rotational velocity of 194 km/s. Omicron Herculis is both a spectroscopic and an interferometric binary star with a separation of 0.1 arcsec. Omicron Hercules is notable for residing close to the coordinates of the solar apex, the direction towards which the Sun is moving.
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At least 23 eruptions have occurred throughout its eruptive history. This volcanic activity ranged from effusive to explosive, with magma compositions ranging from basaltic to rhyolitic. Because the Mount Cayley volcanic field has a high elevation and consists of a cluster of mostly high altitude, non-overlapping volcanoes, subglacial activity is likely to have occurred under less than of glacial ice. The style of this glaciation promoted meltwater escape during eruptions.
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For the purposes of this list, the summits must be an actual eruptive volcanic center, not merely made of volcanic rocks which were uplifted by other geological processes. In addition, a topographic prominence of at least is required, so that the list includes only genuine volcanic mountains and not minor outpourings of lava which happened to leak to the Earth's surface in high-altitude regions (see Asia below).
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If a magma body on Mars is to reach close enough to the surface to erupt before solidifying, it must be big. Consequently, eruptions on Mars are less frequent than on Earth, but are of enormous scale and eruptive rate when they do occur. Somewhat paradoxically, the lower gravity of Mars also allows for longer and more widespread lava flows. Lava eruptions on Mars may be unimaginably huge.
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Various islands or island groups in the Atlantic were also identified as possible locations, notably the Azores. Similarly, cores of sediment covering the ocean bottom surrounding the Azores and other evidence demonstrate that it has been an undersea plateau for millions of years.Huang, T.C., N.D. Watkins, and L. Wilson, 1979, Deep-sea tephra from the Azores during the past 300,000 years: eruptive cloud height and ash volume estimates.
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The Miravalles Volcano is an andesitic stratovolcano in Costa Rica. The caldera was formed during several major explosive eruptions that produced voluminous dacitic-rhyolitic pyroclastic flows between about 1.5 and 0.6 million years ago. The only reported historical eruptive activity was a small steam explosion on the SW flank in 1946. High heat flow remains, and Miravalles is the site of the largest developed geothermal field in Costa Rica.
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It appears that continental accretion sediments, if carried by the downgoing plate into a subduction zone, will jam it up and cause subduction to cease, resulting in the rebound of the accretionary prism with fore-arc lithosphere (ophiolite) on top of it. Ophiolites with compositions comparable with hotspot-type eruptive settings or normal mid-oceanic ridge basalt are rare, and those examples are generally strongly dismembered in subduction zone accretionary complexes.
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Its three principal summits visible from the Central Valley give it the common local name of Las Tres Marías (The Three Marys). Four pyroclastic cones are present within the 2 x 3 km caldera at the central and northwestern part of the summit. The southwestern peak contains four cones, one of which has a crater lake. The last confirmed eruptive activity at Barva Volcano has been dated to 8,050 years ago.
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Using these assumptions and tree-ring measurements, Finch proposed a complex and detailed eruptive chronology for Cinder Cone that spanned nearly 300 years. From measurements of the rings of one particular tree, which showed two periods of slow growth, he thought that the two explosive eruptions occurred in 1567 and 1666. He also concluded that the five lava flows were extruded in 1567, 1666, 1720, 1785, and 1851.
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A later form of the disease occurred in patients who survived for 8–10 days (variolosa pustula hemorrhagica). The prodrome is severe, similarly to early hemorrhagic smallpox, and continues even after the rash begins, like in flat smallpox. The fever remained elevated throughout the disease course. The hemorrhages appeared in the early eruptive period, and the rash was often flat and did not progress beyond the vesicular stage.
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It is also called the eruptive phase or tissue phase, in which the patients develop a cutaneous rash produced by a proliferation of endothelial cells and is known as "Peruvian warts" or "verruga peruana". Depending on the size and characteristics of the lesions, there are three types: miliary (1–4 mm), nodular or subdermic, and mular (>5mm). Miliary lesions are the most common. The lesions often ulcerate and bleed.
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Glaciers were present on the volcano until the conclusion of the Little Ice Age, at the beginning of the 20th century. Pleistocene glaciers have largely eroded Thielsen's caldera, exposing its contents. The small Lathrop Glacier in the northern cirque of the volcano is the only extant glacier on Mount Thielsen. While the glaciation was extensive, volcanic ash from eruptive activity at Mount Mazama has almost certainly masked contents.
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Since its eruption stopped about 250,000–100,000 years ago, the period of eruptive activity was short in time. The eruptions of the cone came in three phases: a period where lava flows built up its cone, one where more explosive pyroclastic eruptions took place, and the final period, in which pyroclastic and material of lava-based origin were erupted together forming a weak cone encircled by long deposits.
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Plate tectonics of the Cascade Range The early eruptive stages of Mount St. Helens are known as the "Ape Canyon Stage" (around 40,000–35,000 years ago), the "Cougar Stage" (ca. 20,000–18,000 years ago), and the "Swift Creek Stage" (roughly 13,000–8,000 years ago). The modern period, since about 2500 BCE, is called the "Spirit Lake Stage". Collectively, the pre–Spirit Lake stages are known as the "ancestral stages".
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Graph summarizing the eruptions of Kïlauea during the past 200 years. The Pu‘u ‘Ö‘ö- Kupaianaha eruption has continued into the 21st century. Information is sketchy for eruptions before 1823, when the first missionaries arrived on the Island of Hawai‘i. The total duration of eruptive activity in a given year, shown by the length of the vertical bar, may be for a single eruption or a combination of several separate eruptions.
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The AAVSO International Variable Star Index defines a LERI type of variation. λ Eri is classified as LERI + GCAS since it shows both short term periodic variations and longer timescale eruptive variation. It was one of the first stars where short-period variations were found. The line profile variability periods are 0.702d and 0.269d, with intermittently present periods of 0.6d and 0.75d. The photometric amplitude of the variation is 0.010 magnitude.
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The volcano is located in the Central Volcanic Zone, an area of volcanism in the Andes. Volcanism in this area is dependent on the subduction in the Peru-Chile Trench. 27 million years ago, in this area of the Andes large rhyolitic eruptions commenced and formed major ignimbrites, dramatically increasing 10 million years ago. At the same time starting in the Miocene, andesitic to dacitic eruptive activity has formed large stratovolcanoes.
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At least 54 eruptions have occurred at the massif in the last 2,600,000 years, ranging in character from effusive to explosive. Four primary eruptive periods have been identified, with individual eruptions separated by thousands of years. Large northwest–southeast trending structures paralleling Harrison Lake and the Pemberton Valley may control volcanic activity at the volcano or at least create zones of crustal weakness that are penetrated by rising magma batches.
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Volcanic activity of the third eruptive period occurred between 1,100,000 and 200,000 years ago. A thick sequence of andesite lava flows were erupted from the volcanic plug of Devastator Peak, creating the Pylon Assemblage. With a maximum thickness of more than , the Pylon Assemblage is the largest rock unit comprising the Mount Meager massif. The lava flows are layered, separated by a thin layer of lapilli tuff and reddened breccia.
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The fourth and final eruptive period 150,000 to less than 3,000 years ago produced rhyodacite lava flows, domes, breccias and subvolcanic intrusions of the Plinth, Job and Capricorn assemblages. Around Mount Job, porphyritic hornblende, biotite and quartz rhyodacite lava flows of the Job Assemblage were erupted. They are prominently layered and locally columnar jointed. On the east side of Affliction Glacier, they overlie porphyritic andesite lava flows of the Pylon Assemblage.
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From 1989 to 1991, Glicken continued his volcanological studies in Japan as a postdoctoral fellow at the Earthquake Research Institute of the University of Tokyo, supported by grants from the U.S. National Science Foundation. Later, while a research professor and translatorThompson, p. 154. at Tokyo Metropolitan University, Glicken became involved with research at Mount Unzen. The volcano had recently resumed eruptive activity in November 1990, after being dormant for 198 years.
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Today, the volcano lies dormant within Nisga'a Memorial Lava Beds Provincial Park. Gases currently being emitted by the volcano are evidence that the volcano is still active and potentially dangerous. Signs of unrest such as seismic activity and increased gas output will almost certainly precede any future eruptive activity from the Tseax Cone. If the Tseax Cone were to erupt, its effects would be felt throughout the interior of British Columbia.
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The Banks Peninsula Volcano is an extinct volcanic complex to the east of Christchurch on New Zealand's South Island.Sewell 1986 While the volcano is highly eroded it still forms the majority of Banks Peninsula with a highest point of . It is a composite of two main eruptive centers one originating at Lyttelton Harbour, the other at Akaroa Harbour. The eruptions were predominantly basaltic, with associated andesite and trachytes, with minor rhyolite.
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The ʻAilāʻau eruption is a prehistoric eruption of Kīlauea volcano on the island of Hawaiʻi in the Hawaiian Islands. Carbon 14 dated from approximately 1410 to 1470 with an eruptive volume of 5.2 ± 0.8 km3 and fed by lava tubes near Kīlauea Iki crater, it was among the last of a series of highly voluminous lava flows since about 1290 that blanketed vast swaths of what is now Hawaii County's Puna District. The Kazumura Cave lava tubes were also created by this eruption.Kilauea summit overflows: Their ages and distribution in the Puna District, Hawai'i - USGSGEOL205: Kiluea [sic] eruptive history - Ken Hon, Ph.D., Professor of Geology, University of Hawai'i at Hilo The ʻAilāʻau eruption occurred before written records, but was witnessed by Ancient Hawaiians, and through their oral traditions it is thought to have inspired the Hawaiian myth of ʻAilāʻau, whose name in the Hawaiian language means "forest-eater" in reference to the many forest lands consumed by lava.
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Those who survive the acute phase of TEN often suffer long-term complications affecting the skin and eyes. Skin manifestations can include scarring, eruptive melanocytic nevi, vulvovaginal stenosis, and dyspareunia. The epithelium of the trachea, bronchi, or gastrointestinal tract may be involved in SJS and TEN. Ocular symptoms are the most common complication in TEN, experienced by 20–79% of those with TEN, even by those who do not experience immediate ocular manifestations.
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The Keanakakoi eruption was a VEI-4 eruption that occurred from the summit caldera of Kīlauea volcano in or around November 1790. It has been described as the deadliest volcanic eruption in what is now the United States, with more than 400 people having been killed in the event. The eruption deposited the Keanakakoi Ash which surrounds the Kīlauea Caldera. Three eruptive phases define the Keanakakoi eruption, all of which were separated by quiescent spells.
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On March 6, 2018, after observing a decline in volcanic activity, PHIVOLCS-DOST downgraded the alert level back to Alert Level 3. On March 29, 2018, after observing a further decline in activity, PHIVOLCS-DOST lowered the alert level back to Alert Level 2 signifying the end of Mayon's eruptive activity and the volcano's decline to a moderate level of unrest. On December 26, 2018, Mayon caused two phreatic explosions but maintains Alert Level 2.
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After his funding ran out, he temporarily abandoned his research. An eruption from the volcano in 1994 produced pyroclastic flows that killed 63 people, including guests at a wedding ceremony. Returning to Merapi the following year, Voight compared data from the dead and survivors, including the extent of their burn areas, clothing worn, and lung damage. He concluded that protective, long-sleeved clothing and masks enhance chances of survival when exposed to eruptive activity.
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The unusually large thickness of these lava flows is from them ponding and cooling against the Cordilleran Ice Sheet when it still filled valleys at lower elevations. This was the last eruptive activity at Mount Price. The Black Tusk, the oldest and most striking of the three principal volcanoes, is the glacially dissected remains of a stratovolcano that formed between 1.3 and 1.1 million years ago. Eruptions produced hornblende andesite lava flows and lithic tuffs.
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Mount Amiata (La Vetta) is a compound lava dome with a trachytic lava flow that extends to the east. It is part of the larger Amiata complex volcano. A massive viscous trachydacitic lava flow, 5 km long and 4 km wide, is part of the basal complex and extends from beneath the southern base of Corno de Bellaria dome. Radiometric dates indicate that the Amiata complex had a major eruptive episode about 300,000 years ago.
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The Mess Lake Lava Field viewed from the west. Columnar basalts of the Mount Edziza volcanic complex are exposed in the escarpment. Near Mess Lake, inactive hot springs can be found and are most likely associated with the most recent eruptive activity in the Mess Lake Lava Field. Hot springs are closely associated with fumaroles, which are vents in an active volcanic area releasing steam and hot gases, such as sulfur dioxide.
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Fissure swarms of the Krafla spread away from the magma chamber and magma flows along the swarms to the north and south of the volcano. Eruptive fissures within the fissure swarms are most common within 20–30 km distance from the central volcanoes. Fractures within the fissure swarms are common at up to a distance of 70–90 km from the central volcano. Fractures within the fissure swarms are generally subparallel to each other.
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Balsam fir sawfly defoliation does not stimulate the release of buds or shoots, which contributes to a slow recovery and severe impact on the balsam fir. N. abietis outbreaks have been documented to increase in intensity in thinned forests of Atlantic Canada.G. Moreau, E.S. Eveleigh, C.J. Lucarotti, D.T. Quiring (2006). Stage-specific responses to ecosystem alteration in an eruptive herbivorous insect. Journal of Applied Ecology 43: 28-34.G. Moreau, D.T. Quiring (2011).
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This volcanic activity so disruptive to air travel because of a combination of factors: # The volcano was directly under the jet stream. # The direction of the jet stream was unusually stable at the time of the eruption's second phase, continuously southeast. # The second eruptive phase happened under of glacial ice. The resulting meltwater flowed back into the erupting volcano, which created two specific phenomena: ## The rapidly vaporising water significantly increased the eruption's explosive power.
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Visual observations were greatly restricted due to cloud cover over the volcano, but an aeroplane of the Icelandic Coast Guard imaged eruptive craters with radar instruments. A series of vents along a 2-km-long north–south-oriented fissure was active, with meltwater flowing mostly down the northern slopes of the volcano, but also to the south. An ash-loaded eruption plume rose to more than , deflected to the east by westerly winds.
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Historic records mention a series of destructive eruptions in 917 from the volcano at Lake Towada. The eruptive activity peaked on 17 August. Throughout the Heian period the Emishi were slowly subdued by the Imperial Court in Kyoto before being incorporated into Mutsu Province by the Northern Fujiwara around 1094. The Northern Fujiwara set up the port settlement Tosaminato in present- day Goshogawara to develop trade between their lands, Kyoto, and continental Asia.
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He published observations on the geology and mineralogy of Spain and Italy as well as that of central and northern Europe: he wrote on gypsum, pyrites, felspar, tachylite, cordierite and on some eruptive rocks, and devoted much attention to the crystals developed during metallurgical processes In 1816, with Friedrich Stromeyer, he described the mineral allophane.Allophane Mindat.org In 1847 he coined the mineral name biotite in honor of physicist Jean Baptiste Biot.Biotite Mindat.
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Broken Top is a glacially eroded complex stratovolcano. It lies in the Cascade Volcanic Arc, part of the extensive Cascade Range in the U.S. state of Oregon. Located southeast of the Three Sisters peaks, the volcano, residing within the Three Sisters Wilderness, is west of Bend, Oregon in Deschutes County. Eruptive activity stopped roughly 100,000 years ago, and currently, erosion by glaciers has reduced the volcano's cone to where its contents are exposed.
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The placement of fissure sealants on permanent molars without post-eruptive breakdown should be undertaken. Use of a 5th generation bonding adhesive prior to fissure sealant application may improve retention rates of fissure sealants. For partially erupted molars with inadequate moisture control, glass ionomer cements (GIC) can be considered as an interim treatment option. As the retention rate of GIC is often poor, replacement with a resin- based fissure sealant is recommended following tooth eruption.
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Mount McLoughlin from the north Little was known about Mount McLoughlin's geology until the 1970s. Much of what is known today comes from LeRoy Maynard of the Center for Volcanology at the University of Oregon. His work established that the volcano was built over three eruptive phases, each with their own eruption types. James Smith from the United States Geological Survey expanded on Maynard's findings, producing a map of the McLoughlin region.
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Its eruptive history was unknown to most before the pre-eruption volcanic activities of 1991, just before June. Pinatubo was heavily eroded, inconspicuous and obscured from view. It was covered with dense forests which supported a population of several thousand indigenous Aetas. Pinatubo is most notorious for its VEI-6 eruption on June 15, 1991, the second-largest terrestrial eruption of the 20th century after the 1912 eruption of Novarupta in Alaska.
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Pinatubo in April 1991, a few months before the eruption.Photo of Mount Pinatubo Activity of Ancestral Pinatubo seems to have begun about 1.1 million years ago and probably ended tens of thousands of years or more before the birth of "modern" Pinatubo. Much of the rugged land around the present volcano consists of remnants of "ancestral" Pinatubo. It was an andesite and dacite stratovolcano whose eruptive activity was much less explosive than modern Pinatubo.
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Mount Kengamine (剣ヶ峰 Kengamine), one peak on the mountain, was formed in two eruptions 9,600 and 9,200 years ago. Mount Ebisu (恵比寿岳 Ebisu-dake), another peak, was formed during an eruption 2,000 years ago. Though the volcano has lost some of its eruptive power, volcanic gas is still escaping through the Yū River (湯川 Yū- gawa) and there are many spa areas in the surrounding area.
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Mount Mageik is a stratovolcano on the Alaska Peninsula. It has no confirmed historical eruptions (one in 1946 is now deemed questionable), but its youngest eruptive products are apparently Holocene in age (8750 to 500 BCE). A young crater lies on the northeast flank of the central summit cone, and is the site of vigorous superheated fumarolic activity with prominent sulfur deposits. The volcanic cones are composed of andesite, basaltic andesite and dacite.
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Mount Martin is a stratovolcano, located on the Alaska Peninsula, United States, in Katmai National Park and Preserve. It is one of the volcanoes in the vicinity of the Valley of Ten Thousand Smokes. Mount Martin's cone stands only about higher than the surrounding ridge. Although an eruption in 1953 is now considered questionable and no other confirmed eruptive activity has taken place at Mount Martin, there is intense fumarolic activity within its summit crater.
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The Easter hotspot is marked 7 on map. The Easter hotspot is a volcanic hotspot located in the southeastern Pacific Ocean. The hotspot created the Sala y Gómez Ridge which includes Easter Island and the Pukao Seamount which is at the ridge's young western edge. Easter Island, because of its tectonomagmatic features (low eruptive rate, scattered rift zones, and scarce lateral collapses), represents an end-member type of hotspot volcano in this chain.
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The most active volcano in central Philippines, Kanlaon has erupted 30 times since 1819. Eruptions are typically phreatic of small-to-moderate size that produce minor ash falls around the volcano. In 1902, the eruption was classified as Strombolian, typified by the ejection of incandescent cinders, lapilli, lava bombs and gas fumes. However, its eruptive history has not yet been recorded and larger Vesuvian eruptions generated by this stratovolcano has not yet been known.
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Augustine Volcano is a stratovolcano consisting of a central complex of summit lava domes and flows surrounded by an apron of pyroclastic, lahar, avalanche, and ash deposits. The volcano is frequently active, with major eruptions recorded in 1883, 1935, 1963–64, 1976, 1986, and 2006. Minor eruptive events were reported in 1812, 1885, 1908, 1944, and 1971. The large eruptions are characterized by an explosive onset followed by the quieter effusion of lava.
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It has had four historical eruptions, all of which had a VEI of 2. Almost all of its eruptions involved phreatic activity. The latest eruptive activity was a steam explosion in 1888, after small ash eruptions in 1871 and 1873, and earthquakes are not infrequent. A period of seismic unrest in 1996-1997 led an international team of scientists to initiate monitoring of the volcanic unrest, as part of the European Union sponsored Geowarn project.
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Eruptive material from Pico Viejo, Montaña Teide and Montaña Blanca partially fills the Las Cañadas caldera. The last explosive eruption involving the central volcanic centre was from Montaña Blanca around 2000 years ago. The last eruption within the Las Cañadas caldera occurred in 1798 from the Narices del Teide or Chahorra (Teide's Nostrils) on the western flank of Pico Viejo. The eruption was predominantly strombolian in style and most of the lava was ʻaʻā.
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Eruptive vellus hair cysts (or EVHC) are small lesions that occur most often in the chest wall, abdomen and extremities, often with a crusted surface. EVHC may occur randomly, or it can be inherited as an autosomal dominant trait. The condition affects males and females equally, and sporadic cases usually appear at 4–18 years of age. The cysts appear similar clinically to steatocystoma multiplex, as well as acneiform eruptions and milia.
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After volcanism at Brokeoff ended, magmatism became more silicic and began migrating toward Lassen Peak's northern flank. The last 400,000 years have seen at least three known flows, parts of which are still on Raker Peak and Mount Conard. A subsequent explosive eruption ejected of material and created a large crater, which was soon covered by lava. Twelve lava domes were built throughout the area and the next period of eruptive activity began.
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The upper gardens are split by a winding public road, Lovelock Avenue (named for former Dunedin resident, Olympic gold medallist Jack Lovelock). Along each side of this road are bush walks. The upper garden features a geographic plant collection, a small aviary, native plant collection and an extensive rhododendron dell. Also a geological walking trail shows the Dunedin Volcano's different eruptive phases in the upper gardens and along the Water of Leith.
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Since its construction, constant emissions of heat and caustic gases have transformed much of the rock into clays (mostly kaolinite), iron oxides, sulfur-rich compounds and quartz. The present eruptive cone above was constructed sometime between 40,000 to 10,000 years ago. Since that time the volcano has erupted at least ten times, generally from above . One of the more recent flows issued from South Butte and created the long by wide A.G. Aiken Lava Bed.
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The outcrop covers an area of about and an eruptive volume of roughly . The location is heavily forested and the BC Rail mainline passes through the lower portion of the outcrop about above sea level. It represents a feature in the Squamish volcanic field. Mount Garibaldi, one of the larger volcanoes in the southern Garibaldi Belt with a volume of , is composed of dacite lavas that were erupted in the past 300,000 years.
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The Erebus hotspot is a volcanic hotspot responsible for the high volcanic activity on Ross Island in the western Ross Sea of Antarctica. Its current eruptive zone, Mount Erebus, has erupted continuously since its discovery in 1841.Morgan, W.J.; Phipps Morgan, J. (2007) "Plate velocities in hotspot reference frame: electronic supplement". Magmas of the Erebus hotspot are similar to those erupted from hotspots at the active East African Rift in eastern Africa.
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Stream-rounded stones are found on the volcanoes, and were lifted up as the volcanoes grew. Although glaciers were present throughout the Sierra Nevada, they did not reach as far down as the Mono Craters. The most recent eruptive episode on the Mono Craters occurred sometime between the years 1325 and 1365. A vertical sheet-like mass of magma, called a dike, caused groundwater to explosively flash to steam, creating a line of vents long.
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It has a width of and a depth of . Predominantly, it has generated mafic (rich in magnesium and iron) lava, producing about of magma within the past 15,000 years. Moreover, many of the identified eruptive vents from the Quaternary include scoria cones or other mafic vents. The High Cascades graben displays a unique geochemical signature with low-K tholeiite magma and a relatively enriched mantle source, produced by extension and heat flux.
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The field gets its name from the nearby community of Squamish at the north end of Howe Sound on the Sea to Sky Highway. Volcanism in the Squamish field has constructed at least two volcanic zones known as the Watts Point volcanic centre and Monmouth Creek complex. The most recent eruptive activity at these volcanoes is likely Pleistocene in age and are both likely products of glaciovolcanism during the last glacial period.
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On the afternoon of 25 October 2010, Mount Merapi erupted lava from its southern and southeastern slopes. The mountain was still erupting on 30 November 2010, but due to lowered eruptive activity on 3 December 2010, the official alert status was reduced to level 3. The volcano is now 2930 metres high, 38 metres lower than before the 2010 eruptions. After a large eruption in 2010, the characteristic shape of Mount Merapi was changed.
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Map showing volcanoes of Alaska Peninsula. 1953 Eruption There is no evidence of recent eruptive activity at the summit of Trident, nor have there been any reports of historical activity, except fumarolic activity on the east side. The earliest known activity was minor eruptions in 1913, 1949 and 1950. A satellite cone formed February 15, 1953 on the southwest flank of Trident following a major explosive eruption that sent ash to an altitude of over .
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Volcanoes near plate boundaries and mid-ocean ridges are built by decompression melting of rock in the upper mantle. The lower density magma rises through the crust to the surface. Volcanoes formed near or above subducting zones are created because the subducting tectonic plate adds volatiles to the overriding plate that lowers its melting point. Which of these two process involved in the formation of a seamount has a profound effect on its eruptive materials.
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Most eruptions are runny because basaltic magma is less viscous than magmas characteristic of more explosive eruptions such as the andesitic magmas that produce spectacular and dangerous eruptions around Pacific Basin margins. Volcanoes fall into several eruptive categories. Hawaiian volcanoes are called "Hawaiian-type". Hawaiian lava spills out of craters and forms long streams of glowing molten rock, flowing down the slope, covering acres of land and replacing ocean with new land.
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The signs of volcanic activity are still visible on nearby hills. Katmai's most recent eruption was in 1927, but there have been non-eruptive events as recent as 2003. The Alaska Volcano Observatory still monitors Katmai's activity as part of the Katmai Cluster, where there are 5 active stratovolcanos within of Katmai. Visitors to the valley most commonly arrive via bus along the road from Brooks Camp, which is the only road in Katmai Park.
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Night time view of the 1984 eruption At 1:25 a.m., a military satellite recorded a strong infrared signal from the summit of Mauna Loa, indicating that the eruption was underway. Within just a few minutes, people throughout Hawaii island were reporting an intense red glow above the volcano. Eruptive fissures migrated rapidly down the southwest rift zone to the elevation and across the southern half of Moku‘āweoweo (flow A on map).
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The July eruptive episode was preceded by several days of measurable expansion of the summit area, heightened earthquake activity, and changed emission rates of sulfur dioxide and carbon dioxide. The first hit at 5:14 p.m. as an ash column shot and was followed by a faster blast at 6:25 p.m. that pushed the ash column above its previous maximum height in just 7.5 minutes. The final explosion started at 7:01 p.m.
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Eruptive vents on the western edge of the field formed along a fault line that trended to the northeast, located north of present-day Carver. Boring Lava was erupted by vents in the volcanic field, and it has been exposed at elevated topographic levels in intact volcanic cones and dissected lava plains. There is likely more lava deposited under Quaternary sedimentary mantle throughout the region, though activity was confined to a relatively concentrated area.
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The Voragine crater exhibited a lava fountain which reached in height, with an ash plume which reached in height. The activity continued on the following days, with an ash plume that reached in height that forced Catania airport to shut down for a few hours. Volcanic gas emissions from this volcano are measured by a Multi-Component Gas Analyzer System, which detects pre-eruptive degassing of rising magmas, improving prediction of volcanic activity.
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Heart Peaks from the north. The Dudidontu River is in the lower-left corner and the Sheslay River is in the upper-right corner along the Coast Mountains. Little is known about the eruptive history of Heart Peaks because it has not been studied in detail by scientists. The exact age of Heart Peaks is not known, but its first volcanic phase occurred during the Neogene period (between 23 and 2.5 million years ago).
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A popular way of classifying magmatic volcanoes is by their frequency of eruption, with those that erupt regularly called active, those that have erupted in historical times but are now quiet called dormant or inactive, and those that have not erupted in historical times called extinct. However, these popular classifications—extinct in particular—are practically meaningless to scientists. They use classifications which refer to a particular volcano's formative and eruptive processes and resulting shapes.
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These include Lake Werowarp, Lake Coragulac, Lake Gnalinegurk and Lake Purdiguluc. Red Rock, along with Tower Hill, Purrumbete and Leura, is one of the best preserved phreatomagmatic features in Eastern Australia. At least 30 eruptive vents have been identified at the volcano, with the latest known eruption having taken place possibly in 5850 BCE. This makes Red Rock one of the Newer Volcanics Province centres to have been active during the Holocene epoch.
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It shares its compositional group with the Fantastic Lava Beds flows, which represent the last flows erupted at Cinder Cone. Ultimately, the eruptive sequence at Cinder Cone took place over the course of several months. An unusual characteristic of the Fantastic Lava Beds is the presence of anomalous quartz crystal xenocrysts (foreign bodies in igneous rock). Geologists think that they were picked up from wall rocks by the lava as it moved toward the surface.
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Its original and current volumes remain uncertain. It may have had a volume as large as , but erosion has since reduced it to glacially eroded crags. The modern volcano has an estimated volume of and is only a modest fraction of its total output of silicic eruptive products. It has a proximal relief of and a draping relief of , with a nearly vertical cliff more than high immediately above the Turbid Creek valley.
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Squamish would remain evacuated, Highway 99 would remain closed and unrepairable and travel between Whistler/Pemberton and Vancouver would be forced to go via a much longer route to the east. Eruptive activity itself could go on for years, followed by years of declining secondary activity. The cooling lava would intermittently spall sections to produce pyroclastic flows. The fragmental material on the slopes and in valleys would be periodically remobilized into debris flows.
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Because Carrion's disease is often comorbid with Salmonella infections, chloramphenicol has historically been the treatment of choice. Fluoroquinolones (such as ciprofloxacin) or chloramphenicol in adults and chloramphenicol plus beta-lactams in children are the antibiotic regimens of choice during the acute phase of Carrion's disease. Chloramphenicol-resistant B. bacilliformis has been observed. During the eruptive phase, in which chloramphenicol is not useful, azithromycin, erythromycin, and ciprofloxacin have been used successfully for treatment.
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The calderas are breached to the east by the Haya-kawa canyon. Mount Ashigara is a parasitic cone. The latest magmatic eruptive activity at Hakone occurred 2,900 years ago. It produced a pyroclastic flow and a lava dome in the explosion crater, although phreatic eruptions took place as recently as the 12–13th centuries AD. According to the nearby Hakone Shrine, the Komagatake peak has been the object of religious veneration since ancient times.
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East Lake has a smaller area of with a maximum depth of . The lakes have historically flooded channels surrounding the volcano. A large flood between 4,000 and 2,300 years ago released up to 12,000 acre feet (0.0148 km3) in volume from Paulina Lake, filling the valley floor above the Paulina Prairie, which surrounds the lake. It was possibly caused by the failure of a rock ledge in height, rather than eruptive activity.
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The two major eruptive episodes were separated by glacial erosion of the volcano. At least during the past 700,000 years, eruptions at the volcano have produced andesitic and dacitic lava. Most of the volcano formed within the past 100,000 years, with the latest activity building the central volcanic cone taking place between 30,000 and 20,000 years ago. These eruptions took place amidst the last glacial period and indicate interaction of lava with ice.
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The symmetrical appearance of St. Helens prior to the 1980 eruption earned it the nickname "Mount Fuji of America". The once familiar shape was formed out of the Kalama and Goat Rocks eruptive periods. Roughly 700 years of dormancy were broken in about 1480, when large amounts of pale gray dacite pumice and ash started to erupt, beginning the Kalama period. The eruption in 1480 was several times larger than the May 18, 1980 eruption.
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The sixth reading (, aliyah) continued the discussion of skin disease on the head or beard. Unclean persons were to rend their clothes, leave their head bare, cover over their upper lips, call out, "Unclean! Unclean!" and dwell outside the camp. When a streaky green or red eruptive affection occurred in wool, linen, or animal skin, it was to be shown to the priest, who was to examine to determine whether it was clean or unclean.
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Seismic swarms (not initiated with a mainshock) are common features at volcanoes, and are rarely associated with eruptive activity. Rainier has had several such swarms; there were days-long swarms in 2002, 2004, and 2007, two of which (2002 and 2004) included M 3.2 earthquakes. A 2009 swarm produced the largest number of events of any swarm at Rainier since seismic monitoring began over two decades earlier. Yet another swarm was observed in 2011.
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Three cycles have been clearly identified, including one subglacial eruption and two post-glacial eruptions. Records show that from 85,000 to 80,000 years ago, activity was more intense than it is today. More than 90% of Hoodoo Mountain, which dates back to at least 100,000 years, formed during its early eruptive history and has grown steadily since then. Regional ice thickness during some of Hoodoo Mountain's subglacial eruptions might have been more than in thickness.
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Two more eruptive cycles took place approximately 1.6 and 1.25 million years ago. The first eruption created the Toledo Caldera, but this feature was largely obliterated by the later Valles eruption. Each eruption involved pyroclastic flows and produced some of the welded tuff now found west of the Rio Grande. There have been numerous eruptions of sticky lavas in the last 1.25 million years ago, but all have been within the Valles Caldera.
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Forsyth 2008 p.29 then extended through the Mount Herbert Volcanic Group to Akaroa Harbour (c.9 Ma).Forsyth 2008 p.29 During the latter phase of the volcano it was simultaneous active from both its major magma chambers, at Akaroa and Lyttelton. The complex geochemically evolved over time and has cyclic eruptive phases. Each packed has an increase feldspar with time, which created more blocky lava flows due to increased viscosity.
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The amoeboid stage is roughly cylindrical, typically around 20-40 μm in length. They are traditionally considered lobose amoebae, but are not related to the others, and unlike them, do not form true lobose pseudopods. Instead, they advance by eruptive waves, where hemispherical bulges appear from the front margin of the cell, which is clear. The flagellate stage is slightly smaller, with two or four anterior flagella anterior to the feeding groove.
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Other forms of solar activity frequently associated with coronal mass ejections are eruptive prominences, coronal dimming, coronal waves and Moreton waves, also called solar tsunami. Magnetic reconnection is responsible for CME and solar flares. Magnetic reconnection is the name given to the rearrangement of magnetic field lines when two oppositely directed magnetic fields are brought together. This rearrangement is accompanied with a sudden release of energy stored in the original oppositely directed fields.
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This range includes at least nine caldera complexes, more than 70 of Chile's stratovolcanoes and volcanic fields that have been active in the Quaternary, and hundreds of minor eruptive centers. The South Volcanic Zone is the most volcanically active region in Chile, and produces around one eruption per year. Its largest historical eruption was at Quizapu Crater, located to from the north side of Cerro Azul's summit, and its most active volcanoes are Llaima and Villarrica.Stern et al.
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Before 1970, little was known about the mountain. Minor eruptive activity began in 1970 and melted parts of the glacier, raising river water levels and leading to the identification of the caldera. In August–September 1971, a moderate eruption (VEI 3) located in the northwest area of the caldera sent ash into the air and caused lahars from the melting of a large portion of the glacier. The lahars killed five people; many more were evacuated.
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On 29 October 1971, at 4:00 am, there were several explosions in the crater and a column of white and then black smoke appeared. One month later, at quarter to midnight on 29 November, Villarrica began a new eruptive cycle. Pyroclasts were ejected and the snow surrounding the crater melted. After a brief halt in activity lava poured from a new vent on the north-east side, melting considerable amounts of water and causing lahars.
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This form of volcanism creates a monumental relief shaped as stairs of pyramids. Other forms of volcanism are present locally, such as the strombolian volcano Mont Ross, and the volcano- plutonic complex on the Rallier du Baty peninsula. Various veins and extrusions of lava such as trachytes, trachyphonolites, and phonolites are common all over the islands. No eruptive activity has been recorded in historic times, but some fumaroles are still active in the south-west of Grande-Terre island.
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Mount Garibaldi as seen from the town of Squamish Three principal volcanoes comprise the southern segment along with several smaller edifies. The largest and youngest principal volcano, Mount Garibaldi, is a dissected stratovolcano that began its formation 250,000 years ago. This eruptive period built a broad composite cone made of dacite and breccia. Parts of this "proto-Garibaldi" or ancestral volcano are exposed on Garibaldi's lower northern and eastern flanks and on the upper of Brohm Ridge.
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When lava flows were erupted from Tuber Hill, they interacted with the valley-filling glaciers on its southern flank and produced a glacial meltwater lake. Here, more than of stacked hyaloclastite, lahars and lacustrine tuff were deposited. A series of pillow lavas were also deposited during this eruptive period. The most recent volcanic activity in the Bridge River volcanic field produced a series of basaltic lava flows in the regional valleys that overlie till of the last glacial period.
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Mess Lake Cone is a cinder cone in northwestern British Columbia, Canada. It is polygenetic in nature, having erupted more than once throughout its eruptive history.Catalogue of Canadian volcanoes: Mess Lake Mess Lake Cone is one of the volcanoes that produced young basaltic lava flows in the central portion of the Mount Edziza volcanic complex in the past 10,000 years. These basaltic lava flows form a north–south trending volcanic field called the Mess Lake Lava Field.
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In main-sequence stars major eruptive variability is exceptional. It is common only among the flare stars, also known as the UV Ceti variables, very faint main-sequence stars which undergo regular flares. They increase in brightness by up to two magnitudes (six times brighter) in just a few seconds, and then fade back to normal brightness in half an hour or less. Several nearby red dwarfs are flare stars, including Proxima Centauri and Wolf 359.
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Northeast face of Mount Silverthrone Very little is known about Silverthrone's eruptive history. However, as at other calderas, eruptions at Silverthrone are explosive in nature, involving viscous magma, glowing avalanches of hot volcanic ash and pyroclastic flows. The source magma of this rock is classified as acidic, having high to intermediate levels of silica, as in rhyolite, dacite, and andesite. Andesitic and rhyolitic magma are commonly associated with the two forms of explosive eruptions called Plinian and Peléan eruptions.
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Consisting primarily of basaltic andesite, it has a more mafic composition than the other two volcanoes. Its deposits are rich in palagonite and red and black cinders, and they are progressively more iron-rich the younger they are. North Sister's lava flows demonstrate similar compositions throughout the mountain's long eruptive history. The oldest lava flows on North Sister have been dated to roughly 311,000 years ago, though the oldest reliably dated deposits are approximately 119,000 years old.
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Cherry angiomas appear spontaneously in many people in middle age but can also, less commonly, occur in young people. They can also occur in an aggressive eruptive manner in any age. The underlying cause for the development of cherry angiomas is not understood. Cherry angioma may occur through two different mechanisms: angiogenesis (the formation of new blood vessels from pre-existing vessels), and vasculogenesis (the formation of totally new vessels, which usually occurs during embryonic and fetal development).
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It is the second largest persistent eruptive center within the Northern Cordilleran Volcanic Province and is flanked with numerous young satellite cones, including the young, well- preserved Eve Cone. There are some indications that Level Mountain and Mount Edziza volcanic complex may be between 11 and 9 million years old. Map of the Anahim Volcanic Belt centers. The Anahim Volcanic Belt is a volcanic belt that stretches from just north of Vancouver Island to near Quesnel.
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He was distinguished for his researches on minerals and on crystallography, and he was one of the earlier workers on microscopic petrography. He described in 1878 the eruptive rocks of the district of Saar and Moselle. In 1880 he edited "Der Aetna" from the manuscripts of Wolfgang Sartorius von Waltershausen, the results of observation made between the years 1834 and 1869. He was author of "Elemente der Petrographie" (1875), "Einführung in die Gesteinslehre" (1885), and "Précis de petrographie" (1887).
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These eroded areas exhibit pyroclastic rock in a matrix with lava flows, suggesting that blocky and ʻaʻā lavas formed an outer shell around Pelican Butte's fragmented interior. Glaciation has also lowered the overall volcano by tens of yards. Other volcanoes can be found within the Sky Lakes Wilderness area, including lava flows and mud flows at Big Bunchgrass Butte and Imagination Peak, in addition to more recent eruptive activity at Goosenest Mountain in the northeastern sector.
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Goat Rocks volcano as seen from Mount Adams vicinity Goat Rocks is a stratovolcano with a somewhat complicated eruptive history. It first became active approximately 3.2 million years ago during the Pliocene epoch, undergoing explosive eruptions that ejected silicic lava with highly felsic rocks like rhyolite. One of these events produced of tuff that remains, exposed, on the east flank of the existing mountain. Three million years ago Goat Rocks shifted to mafic volcanism, erupting olivine and basalt.
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Mentolat is an ice-filled, wide caldera in the central portion of Magdalena Island, Aisén Province, Chilean Patagonia. This caldera sits on top of a stratovolcano which has generated lava flows and pyroclastic flows. The caldera is filled with a glacier. Little is known of the eruptive history of Mentolat, but it is thought to be young, with a possible eruption in the early 18th century that may have formed lava flows on the western slope.
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Image of the rhyolitic lava dome of Chaitén Volcano during its 2008-2010 eruption. Chaitén is a volcanic caldera in diameter, west of the elongated ice-capped Michinmahuida volcano and northeast of the town of Chaitén, near the Gulf of Corcovado in southern Chile. The most recent eruptive phase of the volcano erupted on 2008. Originally, radiocarbon dating of older tephra from the volcano suggested that its last previous eruption was in 7420 BC ± 75 years.
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Stefanos, the largest crater of the volcano. Landscape The island has a wide caldera, and was formed within the past 150,000 years, with three separate eruptive stages, ranging from explosive and effusive andesitic eruptions to explosive and effusive dacitic and rhyolitic activity. Its coasts are generally rocky or pebbled, but there are also a few sandy beaches (mainly in the northeastern part). The volcano is currently active but not erupting, and fumaroles are found at the craters.
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The initial juvenile stage was followed by a period of 2–3 million years of eruptive quiescence and erosion. This cessation of activity is typical of the Canaries; La Gomera, for example, is currently at this stage.Paris, R, Guillou, H., Carracedo, JC and Perez Torrado, F.J., Volcanic and morphological evolution of La Gomera (Canary Islands), based on new K-Ar ages and magnetic stratigraphy:implications for oceanic island evolution, Journal of the Geological Society, May 2005, v.162; no.
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Eruptive activity in the Northern Cordilleran Volcanic Province throughout its 20 million year history has been mainly the production of alkaline lavas, including alkaline basalts. A range of alkaline rock types not commonly found in the Western Cordillera are regionally widespread in the Northern Cordilleran Volcanic Province. These include nephelinite, basanite and peralkaline phonolite, trachyte and comendite lavas. The trachyte and comendite lavas are understood to have been created by fractionation of mainly alkali basalt magma in crustal reservoirs.
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Volcanic activity at Anak Krakatau, 2008 2010: The thick brown plume of ash, steam and volcanic gas rising from Anak Krakatoa in this true-colour satellite image is a common sight at the stratovolcano. Until its 2018 collapse, Anak Krakatau had grown at per week on average since the 1950s. This equates to an average growth of per year. The island remains active in January 2019, with its most recent eruptive episode having begun in 1994.
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1995 eruption of Mount Rinjani in IndonesiaThe Smithsonian Institution's Global Volcanism Program (GVP) documents Earth's volcanoes and their eruptive history over the past 10,000 years. The GVP reports on current eruptions from around the world as well as maintaining a database repository on active volcanoes and their eruptions. In this way, a global context for the planet's active volcanism is presented. Smithsonian reporting on current volcanic activity dates back to 1968, with the Center for Short-Lived Phenomena (CSLP).
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In May 1907, Lassen Peak was declared a national monument by President Theodore Roosevelt to protect the area for "future generations to study and enjoy".Harris, Tuttle, and Tuttle, p. 542. Roosevelt had been told that the area was actually extinct in terms of eruptive activity. Despite assurance from Native Americans in the area that the mountain was indeed active, settlers continued to think that Lassen Peak was extinct and "dead" and so continued to settle nearby.
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Another tuff is found in Quebrada Cusi Cusi. Above these lies an eastward sloping layer of volcaniclastic material. The area covered by the Panizos products had been subject to earlier eruptive activity from unknown centres between 15.4–13.4 mya, generating tuffs recognized in the San Pablo de Lípez region as outcrops. Changes in the subduction geometry since the late Miocene have caused volcanism to diminish from east to west, including cessation of activity at the Panizos centre.
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Blue Lake Crater has a mafic composition (rich in magnesium and iron). Blue Lake Crater's major rock composition components are basalt and picrite basalt (picrobasalt). Analysis of components from Blue Lake Crater eruptive deposits for calc-alkaline melt inclusion showed compositional similarities with the Yapoah and Collier cones, indicating that Blue Lake Crater is also made up of basaltic andesite. By weight percentage, Blue Lake Crater deposits consist of about 54% Silicon dioxide (silica) and about 5% magnesium oxide.
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Eruptions of basalt and andesite 400,000 to 60,000 years ago in the west moat of Long Valley Caldera were the first activity associated with the Mono–Inyo Craters system. Eruptions around 300,000 years ago filled the west moat with of basaltic lava. Basaltic and andesitic eruptive activity then moved to Mono Basin and lasted from 40,000 to 13,000 years ago. Seismic data indicate that a magma chamber with an estimated volume of exists directly below the Mono Craters.
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The 1902 eruption of Mount Pelée was a moderately large volcanic eruption on the island of Martinique in the Lesser Antilles Volcanic Arc of the eastern Caribbean. Eruptive activity began on 23 April as a series of phreatic explosions from the summit of Mount Pelée. Within days, the vigor of the explosions exceeded anything witnessed since the island was settled by Europeans. The intensity then subsided for a few days until early May when the explosions had increased again.
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1943 eruption at night Parícutin erupted from 1943 to 1952, unusually long for this type of volcano, and with several eruptive phases. For weeks prior, residents of the area reported hearing noises similar to thunder but without clouds in the sky. This sound is consistent with deep earthquakes caused by the movement of magma. A later study indicated that the eruption was preceded by 21 earthquakes over 3.2 in intensity starting five weeks before the eruption.
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He opined that Anthrax sounded rejuvenated and qualified the album as a return to form. Chad Grischow of IGN commented that the album sounded "as fresh and eruptive as ever" with the exception of "Crawl", the "rare misstep on the otherwise fantastic album". Loudwire's Matthew Wilkening said that Belladonna's 20-year absence from the band hasn't affected the band's chemistry at all. According to him, the album represented the maturity and musical growth of the band.
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Wallender Born is the result of volcanic activity seen in the Eifel region, although the shape of the eruptive source is not a direct consequence of geothermal energy, but of the escape of carbon dioxide. From the magma in the crust volcanic gas rises through cracks and fissures in the earth's surface and dissolves partly in the ground water to carbonic acid. The source is a calcium-sodium-bicarbonate-sorrel. The spring water is very cloudy with sediment.
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Olallie Butte is at least 25,000 years old, making it of Pleistocene age. It was likely built up by eruptions prior to the last glacial period. Comparisons of its morphology with Mount Jefferson suggest an age between 70,000 and 100,000 years. Thayer (1939) grouped eruptive activity at Olallie Butte with deposits at Mount Jefferson, Mount Hood, and Crater Lake (Mount Mazama) into the Olallie Lava group, which display highly variable thicknesses ranging from extremely thin to up to .
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Eruptive activity has moved southward over the history of Taapaca, with activity centred at the top of the edifice. Late Pleistocene to Holocene activity consisted of discrete episodes lasting about 10,000 years and separated by tens of thousands of years with no recognized activity. Aside from actual eruptions, various types of edifice collapse are recorded at Taapaca including sector collapses of segments of the volcano and mass failure of individual domes, which generated block-and-ash flows.
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Some damage was caused by a minor eruption in 1821. Notably, the ash released from the eruption contained a large fraction of fluoride, which in high doses may harm the bone structure of cattle, horses, sheep and humans. The eruption also caused some small and medium glacier runs and flooding in nearby rivers Markarfljót and Holtsá. The eruptive phase started on 19 and 20 December 1821 by a series of explosive eruptions and continued over the next several days.
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On February 19, 1965 a non-eruptive landslide of ice and rock caused by unusually heavy summer rains slid rapidly into a narrow gully, descended around 1500 meters in elevation, and crashed into Lake Cabrera below. This triggered a tsunami that thundered across the lake and swept through the lakeside community of Lago Cabrera just moments later. There was virtually no warning and the community was caught by surprise. The entire village was destroyed, killing twenty-seven people.
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Amateur image of γ Cassiopeiae and the associated nebulae IC63 and IC59 (Neil Michael Wyatt) Gamma Cassiopeiae is an eruptive variable star, whose apparent magnitude changes irregularly between +1.6 and +3.0. It is the prototype of the class of Gamma Cassiopeiae variable stars. In the late 1930s it underwent what is described as a shell episode and the brightness increased to above magnitude +2.0, then dropped rapidly to +3.4. It has since been gradually brightening back to around +2.2.
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Culminating at an altitude of 298 meters, the Ardoukôba is a volcano born from a volcanic fissure and composed of a pile of basaltic slag forming three cones emitting two flows of fluid basaltic lava. These eruptive characteristics classify the Ardoukôba among the red volcanoes fed by a rift magma. This northwest-southeast trending volcanic fissure is part of the Great Rift Valley fault system between the Danakil block in the northeast and the Afar depression in the southwest.
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Mount Thielsen, or Big Cowhorn (Klamath: hisc’akwaleeʔas), is an extinct shield volcano in the Oregon High Cascades, near Mount Bailey. Because eruptive activity ceased 250,000 years ago, glaciers have heavily eroded the volcano's structure, creating precipitous slopes and a horn-like peak. The spire-like shape of Thielsen attracts lightning strikes and creates fulgurite, an unusual mineral. The prominent horn forms a centerpiece for the Mount Thielsen Wilderness, a reserve for recreational activities such as skiing and hiking.
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The debris avalanche was up to in volume. The Mount St. Helens National Volcanic Monument was created to preserve the volcano and allow for the eruption's aftermath to be scientifically studied. As with most other volcanoes in the Cascade Range, Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash, pumice, and other deposits. The mountain includes layers of basalt and andesite through which several domes of dacite lava have erupted.
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Two views of Halemaʻumaʻu from roughly the same vantage point. At left is the view from 2008, with a distinct gas plume from the Overlook vent, the location of what would become a long-lived lava lake. At right is a view of Halemaʻumaʻu after the eruptive events of 2018, showing the collapsed crater. Together with the outbreak of lava in lower Puna, a lava lake at Halemaʻumaʻu at Kilauea's summit began to drop on May 2, 2018.
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The long-haired rat (Rattus villosissimus), is a species of rodent in the family Muridae which is native to Australia. The long-haired rat is well known for its population eruptions over vast areas of Australia which is the basis of its alternative common name, the plague rat. Most of the research on the long-haired rat has been conducted during times of massive population fluctuations and therefore little is known about their biology in a non- eruptive period.
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New Beach on Kaimū Bay, formed by volcanic flows in 1990, as seen in 2009. Kaimū was a small town in the Puna District on Island of Hawaii that was completely destroyed by an eruptive flow of lava from the Kūpaʻianahā vent of the Kīlauea volcano in 1990. In Hawaiian, kai mū means "gathering [at the] sea" as to watch surfing.; The lava flow that destroyed Kaimū and nearby Kalapana erupted from the southeast rift zone of Kīlauea.
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American astronomer Halton Arp included it in his 1966 Atlas of Peculiar Galaxies. In 1971, Swiss astronomer Fritz Zwicky described it as a "blue post-eruptive galaxy, compact patchy core, spiral plumes, long blue jet SSW". In the De Vaucouleurs system for classifying galaxies, NGC 1614 has a galaxy morphological classification of SB(s)c pec. The SB indicates this is a barred spiral galaxy, while the '(s)' means it lacks a ring-like structure around the nucleus.
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German) The Siberian Traps (, ) is a large region of volcanic rock, known as a large igneous province, in Siberia, Russia. The massive eruptive event that formed the traps is one of the largest known volcanic events in the last years. The eruptions continued for roughly two million years and spanned the Permian–Triassic boundary, or P–T boundary, which occurred between ."New Studies of Permian Extinction Shed Light On the Great Dying", New York Times, April 30, 2012.
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Condensation of ambient moisture (moisture already present in the atmosphere), as well as moisture evaporated from burnt vegetation or volcanic outgassing (water vapour is a dominant component of volcanic eruptive gases), occurs readily on particles of ash. Wildfire in Yellowstone National Park produces pyrocumulus clouds. Flammageniti contain severe turbulence, manifesting as strong gusts at the surface, which can exacerbate a large conflagration. A large flammagenitus, particularly one associated with a volcanic eruption, may also produce lightning.
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They were created during several volcanic episodes involving a variety of eruptive styles ranging from passive lava eruptions to viscous explosive eruptions. Part of the Canadian Shield, the TGB contains some of the oldest known rocks on Earth. The belt is made up of a number of geologic features such as batholiths, stocks, dikes, volcanic complexes, layered intrusions and deformation zones. These are situated in several geographical townships in the municipality of Temagami, including Chambers, Strathy, Strathcona, Briggs and possibly Best.
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Mount Vesuvius is the only active volcano on the European mainland, while others, Mount Etna and Stromboli, are on neighbouring islands. The region around Vesuvius including the Phlegraean Fields Caldera west of Naples are quite activeAntonio Denti, "Super volcano", global danger, lurks near Pompeii, Reuters, 3 August 2012. and constitute the most densely populated volcanic region in the world where an eruptive event may occur within decades. Vesuvius itself is regarded as quite dangerous due to a tendency towards explosive (Plinian) eruptions.
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USGS Map of Historic Flows 1983–April, 2008 The Puu Ōō eruption began when fissures split the ground in the remote rainforest of the eastern rift zone, on January 3, 1983. By June 1983, the activity had strengthened and localized to the Puu Ōō vent. Over the next three years, 44 eruptive episodes with lava fountains as high as stopped traffic at points across east Hawaii. The fallout of cinder and spatter from the towering lava fountains built a cone high.
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More northerly populations of Lewis's woodpecker, northern flicker, Williamson's sapsucker, red-breasted sapsucker and red-naped sapsucker all move southwards in the fall in North America. Most woodpecker movements can be described as dispersive, such as when young birds seek territories after fledging, or eruptive, to escape harsh weather conditions. Several species are altitudinal migrants, for example the grey-capped woodpecker, which moves to lowlands from hills during the winter months. The woodpeckers that do migrate do so during the day.
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This is evidence of explosive eruptions during Fee's eruptive history, as well as its first volcanic event. The second volcanic event produced a sequence of volcanic rocks on Fee's eastern flank. This volcanic material was likely deposited when a sequence of lava flows and broken lava fragments erupted from a volcanic vent and moved down the flanks during the construction of the ancestral Mount Fee. Following extensive dissection, renewed volcanism produced a viscous series of lavas on its northern flank.
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Willaertia has 3 distinct life stages including an amoeboid stage, a temporary flagellated stage, and a cyst stage that it alternates between. Willaertia amoebae are large, often between 50-100 μm. As typical heteroloboseans they have eruptive pseudopods when moving, and as typical vahlkampfiids they form a prominent uroid due to cytoplasmic shifts. Willaertia amoebae have been observed to have spherical and elongated mitochondria that show an unusual crista formation characterized by perforated plates that are either in parallel or alternately packed tubes.
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The 1991 eruption of Mount Pinatubo in the Philippines' Luzon Volcanic Arc was the second-largest volcanic eruption of the 20th century, behind only the 1912 eruption of Novarupta in Alaska. Eruptive activity began on April 2 as a series of phreatic explosions from a fissure that opened on the north side of Mount Pinatubo. Seismographs were set up and began monitoring the volcano for earthquakes. In late May, the number of seismic events under the volcano fluctuated from day-to-day.
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Following the emplacement of late Pliocene lava domes, lesser activity continued into the Quaternary period (2.58 million years ago to present). Initial volcanism began on the summit of the volcano, depositing lava in and adjacent to the Level Mountain Range. This activity is indirectly dated as Pleistocene age , on the bases of the presence of subglacial and/or intraglacial deposits. Meszah Peak, the highest point of both Level Mountain and the Level Mountain Range, was volcanically active during this eruptive period.
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Todd Lake volcano, which erupted porphyritic andesite (andesite with distinct differences among its crystal size) with a pale gray color, sits at Broken Top's southern foot. Its lava flows have been exposed and are covered with red scoria and agglutinate from a separate volcanic vent. It began to erupt as Broken Top stopped eruptive activity, since the two have overlapping layers of lava. As Pleistocene glaciers retreated, basaltic cinder cone volcanoes formed south of Todd Lake right as Cayuse Crater was forming.
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Post-eruptive breakdown (PEB) is a clinical feature, often observed in the majority of severely affected cases. The rate of PEB may be increased by the loading of masticatory forces on enamel weakened by MIH. The lesions resulting from PEB are irregularly shaped, with rough margins from the shearing of the enamel. PEB is more likely to occur in MIH affected teeth with yellow or brown opacities rather than those with white opacities, as darker lesions reflect a greater deficit in mineral content.
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This erupted from fissures that were geographically spread throughout eastern Washington, eastern Oregon, and far western Idaho. Most of the lava erupted between 17 and 14 million years ago, with smaller eruptions lasting as late as 6 million years ago. The nearest eruptive vent to Kennewick from this period is near Ice Harbor Dam along the Snake River upstream of Burbank and Pasco. While outcroppings from the basalt flows can be seen throughout Kennewick, they are mostly buried by sediments.
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The San Salvador Volcano (also known as Quezaltepeque or El Boquerón) is a stratovolcano situated northwest to the city of San Salvador. The crater has been nearly filled with a relatively newer edifice, the Boquerón volcano. San Salvador is adjacent to the volcano and the western section of the city actually lies among its slopes. Due to this close proximity, any geological activity of the volcano, whether eruptive or not, has the potential to result in catastrophic destruction and death to the city.
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Its total eruption volume is estimated to be . Future eruptions from The Volcano will probably be similar in character to those that have occurred throughout its 360-year eruptive history. There is a one in 200 chance per year of an eruption occurring in Canada and one in 220 chance per year of an effusive eruption. An eruption in the foreseeable future is probably more likely along the Northern Cordilleran Volcanic Province than in an unrelated volcanic zone outside the province.
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Archiv für Meteorologie, Geophysik und Bioklimatologie Volumes 29-30 1980 " Most islands of this arc have an active eruptive form: The "Soufrières" of St. Vincent, St. Lucia, Dominica, Guadeloupe and Mt. Pelée on Martinique. The highest point of the lesser Antilles is the soufrière of Guadeloupe with the.." A river separates the town of Soufrière from the Fond Beniere area. A section of the river above the town was canalised and realigned in 1972; the river was realigned again in 1994.
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Large Plinian eruptions could have effects on the city of Arequipa. The Peruvian INGEMMET geological service monitors the seismic activity, any deformation of the mountain, and hot spring and gas composition at Ubinas. It regularly publishes a report on the activity of Ubinas. Hazard maps were created during the 2006 eruptive event to show the relative risk in various locations around the volcano, which is graded in a three-zone scheme with one high-risk, one intermediate-risk and one low-risk zone.
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The remaining product from Fee's earliest volcanic activity is a minor portion of pyroclastic rock. This is evidence of explosive volcanism from Fee's eruptive history, as well as its first volcanic event. The second volcanic event produced a sequence of lavas and breccias on the eastern flank of the main ridge. These volcanics were likely placed when a sequence of lava flows and broken lava fragments erupted from a volcanic vent and moved down the flanks during the construction of a large volcano.
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The park encompasses diverse environments from sea level to the summit of the Earth's most massive active volcano, Mauna Loa, at . Climates range from lush tropical rain forests, to the arid and barren Kaū Desert. Recently eruptive sites include the main caldera of Kīlauea and a more active but remote vent called Puu Ōō. The main entrance to the park is from the Hawaii Belt Road. The Chain of Craters Road leads to the coast, passing several craters from historic eruptions.
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The field includes 23 basaltic and basaltic andesitic cinder cones and lava flows, for a total of 42 volcanic vents within two roughly north–south trending alignments. Its total dense-rock equivalent eruptive output is , with subfeatures including a tephra field and a lava tube system. Future activity is possible, but according to the Volcano Hazards Program of the United States Geological Survey, the threat from the field itself is low. The field lies within the Willamette National Forest near Santiam Pass.
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The remaining products from Fee's earliest volcanic activity is a minor portion of pyroclastic rock. This is evidence of explosive volcanism from Fee's eruptive history, as well as its first volcanic event. The second volcanic event produced a sequence of lavas and breccias on the eastern flank of the main ridge. These volcanics were likely deposited when a sequence of lava flows and broken lava fragments erupted from a volcanic vent and moved down the flanks during the construction of a large volcano.
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Small and probably significant rock avalanches may result and could dam the nearby Squamish River for a limited amount of time, such as those that occurred in the past without seismic activity and deformation related to magmatic activity. At some point the subsurface magma will produce phreatic eruptions and lahars. At this time Highway 99 would be out of service and the residents of Squamish would have to travel away from the eruptive zone. The extent of the Mount Cayley volcanic field.
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At about 420,000 years old, Mount Scott has a conical shape, but has been extensively altered by Pleistocene glacial erosion, which carved a large cirque on its western flank and smaller ones on its eastern and northeastern sides. Scott lacks a summit crater. Hillman Peak was the youngest composite cone in the Mazama eruptive center, forming about 70,000 years ago. It lies on the southwestern side of the caldera, and it represents the highest point on the Mazama rim, rising above Crater Lake.
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Grouse Hill's lava flow deposit and lava dome formed at about the same time, about 27,000 years ago. At the end of this eruptive sequence, rhyodacite lava domes formed on the northeastern slopes of the volcano. Between 100 and 200 years prior to the climactic eruption, Llao Rock, a thick block of dark lava with a volume of , was produced from a rhyodacite flow erupted from Mazama. It has a round center and extensions on the sides, resembling a bird of prey.
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The volcano was born upon an eruption that started on 10 October 2011, at a location 1.8 km to the south of the island of El Hierro, more specifically the settlement of La Restinga. From an initial height of 355 m below sea level, the volcano reached a maximum height of about 88 m below sea level as reported in February 2012. During the eruptive stage the volcano emitted amounts of magma, gases and heat, substantially altering the environment of the maritime area.
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Volcanic bombs are extrusive igneous rocks ranging from the size of books to small cars, that are explosively ejected from stratovolcanoes during their climactic eruptive phases. These "bombs" can travel over away from the volcano, and present a risk to buildings and living beings while shooting at very high speeds (hundreds of kilometers/miles per hour) through the air. Most bombs do not themselves explode on impact, but rather carry enough force so as to have destructive effects as if they exploded.
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At the northwest edge of Harrat Hutaym are marl, sandstone and basal conglomerate deposits with ostracode fossils from a freshwater environment, inferred to be from the Pliocene. Small, similar deposits are scattered across the Rub al Khali. The Al Harrah volcanic complex is the only eruptive feature in the sediment- covered areas of Saudi Arabia. Its olivine basalt and aplite dikes formed during the Miocene, Pliocene and early Quaternary, spanning 250 kilometers to the northwest from Ath Thayat into Jordan.
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These do not exist for volcanoes in British Columbia or elsewhere in Canada in the detail required. Other volcanic techniques, such as hazard mapping, displays a volcano's eruptive history in detail and speculates an understanding of the hazardous activity that could possibly be expected in the future. At present no hazard maps have been created for Mount Garibaldi because the level of knowledge is insufficient due to its remoteness. A large volcanic hazard program has never existed within the Geological Survey of Canada.
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The Reuven Ramaty High Energy Solar Spectroscopic Imager, or RHESSI, combines high-resolution imaging in hard X-rays and gamma rays with high-resolution spectroscopy to explore the basic physics of particle acceleration and energy release in solar flares. Such information improves our understanding of the fundamental processes that are involved in generating solar flares and coronal mass ejections. These super-energetic solar eruptive events are the most extreme drivers of space weather and present significant dangers in space and on Earth.
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Aftermath of the 1994 volcanic eruption in Rabaul In 1983 and 1984 the town was ready for evacuation when the volcanoes started to heat up. Nothing happened until 19 September 1994, when again Tavurvur and Vulcan erupted, destroying the airport and covering most of the town with heavy ashfall. There were only 19 hours of warning, but the city and most nearby villages were evacuated before the eruption. Five people were killed—one of them by lightning from the eruptive column.
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The eruptive cycle of Nazko Cone 7200 years ago started with the eruption of two different progressions of fluid lava flows, an older grey basalt overlain by a younger, darker black basalt. The passive eruptions were followed by a period of explosive eruptions.Natural Resources Canada: Nazko Cone This explosive activity built three overlapping cinder cones near the end of the explosive phase of activity. The last phase of explosive activity spread tephra to the north and east of the cones.
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Phreatomagmatic eruptions are eruptions that arise from interactions between water and magma. They are driven from thermal contraction (as opposed to magmatic eruptions, which are driven by thermal expansion) of magma when it comes in contact with water. This temperature difference between the two causes violent water-lava interactions that make up the eruption. The products of phreatomagmatic eruptions are believed to be more regular in shape and finer grained than the products of magmatic eruptions because of the differences in eruptive mechanisms.
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An FS Canis Majoris variable (FS CMa star) is a type of eruptive variable star. The class of variable stars are named after its prototype, FS Canis Majoris. They are somewhat poorly understood, most likely binary star systems in which mass exchange is ongoing or has recently happened, and most likely consist of at least one B-type main-sequence stars in a dust envelope. They undergo irregular light variations over long periods of time, with magnitude variation of approximately 2 magnitudes.
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Secondary volcanic craters produced lava flows and pyroclastic material, which traveled both north and south of the volcano. Cone-building eruptions ceased before the Pleistocene epoch's glacial period, allowing the expanded glacial cover to remove most of the cone, especially on the eastern and northeastern sides. During the ongoing Holocene epoch, there has been volcanic activity between the Three Sisters volcanoes and Three Fingered Jack. Such eruptive episodes have produced tephra and lava flows that cover several hundred square kilometers in the region.
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All known eruptions at the volcano have had a Volcanic Explosivity Index (VEI) of 3. Despite its activity, Sangay is located in a remote, uninhabited region; only a large Plinian eruption could threaten occupied areas to its west. Nonetheless, a flank collapse on its eastern side, possible given the volcano's construction and history, could displace nearby forest and possibly affect settlements. Access to the volcano is difficult, as its current eruptive state constantly peppers the massif with molten rock and other ejecta.
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North of Pinhead Buttes, the volcanoes in this region are older and less tall, usually between in elevation. South of Pinhead Buttes, the Cascades becomes younger Pleistocene volcanoes, which often have glaciers. Mount Jefferson may form part of a long- lasting intracrustal melting and magma storage area that encompasses an area of , where relatively little mafic eruptive activity has occurred. The melting of the metamorphic rocks amphibolite and at deeper strata, granulite, have both produced intermediate and silicic lavas at Jefferson.
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The period 1967–1968 saw a particularly large, 80-million-cubic-meter, 251-day event from Halemaʻumaʻu. This event was superseded the very next year by the marathon Mauna Ulu eruption, a large effusive eruption which lasted from May 24, 1969 to July 24, 1974 and added of new land to the island. After eruptive activity had died down, there was a magnitude 7.2 earthquake that caused a partial summit collapse, after which activity did not resume at Kīlauea until 1977.
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The Congro system is situated in the central-eastern portion of the island of São Miguel, separated the Água de Pau Massif and crater of the Furnas volcano, and includes scoria cones and lava flows associated with ancient volcanic eruptions. In addition, there are several examples of maars and lava domes. Although it is the least eruptive of the systems forming the island of São Miguel, it has shown a higher frequency of important seismic activities associated with tectonic and volcano-related pressures.
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In contrast to most mountain ranges in British Columbia, the Itcha Range represents an inactive shield volcano. This highly dissected volcanic edifice consists of a variety of rock types, including basanite, hawaiite, trachyte, rhyolite, phonolite and alkali olivine basalt. They were deposited by different types of volcanic eruptions characterized by passive lava flows and explosivity. Two stages of eruptive activity have been identified at the volcano along with three sub-phases that are limited only to the first stage of development.
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The Alto de Las Lagunas ignimbrite is the oldest eruptive unit of Luingo and reaches a thickness of . It was previously named the Hornblendic welded tuff and dated 15.83 ± 0.44 – 14.22 ± 0.33 million years ago; a younger date of 13.52 ± 0.12 million years ago has been obtained on it. This ignimbrite is pink-grey and contains lapilli and crystal-rich fiamme. Minerals include alkaline feldspar, amphibole, biotite, plagioclase and quartz with accessory minerals such as apatite, iron-titanium oxides, sphene and zircon.
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It was probably between and in volume and extended past the reaches of the caldera, down the adjacent foothills. Beyond the caldera, the eruptive products are poor in phenocrysts (unlike those of the first eruption). They are instead rich in lithic material, which makes up as much as 10 percent of the rock in parts (50 percent at the base of the caldera). As the first of the ash was deposited, it accumulated in layers that formed quickly and resisted erosion, but only partially melded together.
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This volcanic system is the most recently formed on the island of São Miguel, with its eruptive history dominated by Hawaiian, basaltic and Stromboli phases. In the last 5000 years, there have been approximately 30 eruptions, with the most recent events occurring with recorded human history. The first, in 1563, succeeded a Phreatoplinian eruption centring on the volcano of Água de Pau. During this 1563 eruption, known as the Pico do Sapateiro or Queimado, basalt lava flows reached as far as Ribeira Seca, in the north coast.
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The special value of these natural riches is given by the great qualitative and quantitative diversity of mineralizations, as well as by the therapeutic (curative) qualities. Mineral waters, due to their complex chemical composition, are natural healing factors with a special therapeutic importance. Waters containing mineral substances and carbon dioxide are waters with a high therapeutic level. The mineral springs in the area resulted from an intense circulation of hydrothermal solutions in the eruptive rocks and in the mass of crystalline rocks and Eocene sedimentary rocks.
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Piton des Neiges is heavily eroded at the summit, nearly erasing its original crater, although it is surrounded by several smaller craters. Almost entirely basalt, the mountain also has small units of andesite, phonolite and trachyte with small alkaline syenite intrusions, forming dikes and sills. In 1981, geologists suggested that volcanism at Piton des Neiges may be closely linked to regional structural geology. The main point of eruptive activity is associated with rift zone strike-slip faults and dike swarms around the mountain indicate cauldron subsidence.
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While classed as eruptive variables, these stars do not undergo periodic increases in brightness. Instead they spend most of their time at maximum brightness, but at irregular intervals they suddenly fade by 1–9 magnitudes (2.5 to 4000 times dimmer) before recovering to their initial brightness over months to years. Most are classified as yellow supergiants by luminosity, although they are actually post-AGB stars, but there are both red and blue giant R CrB stars. R Coronae Borealis (R CrB) is the prototype star.
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However, a benefit-cost examination needs correct data about the hazard types, magnitudes and occurrences. These do not exist for volcanoes in British Columbia or elsewhere in Canada in the detail required. Other volcanic techniques, such as hazard mapping, displays a volcano's eruptive history in detail and speculates an understanding of the hazardous activity that could possibly be expected in the future. At present no hazard maps have been created for the Silverthrone Caldera because the level of knowledge is insufficient due to its remoteness.
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Before the antibiotic era, the only treatment for the acute phase was blood transfusion, but the effectiveness of this treatment was poor and the mortality rate was high. Later, with the discovering of new antibiotics, penicillin, chloramphenicol, tetracycline, and erythromycin have been used successfully. However, because of the risk of overwhelming infections by enterobacteria, quinolones are preferred. Therapeutic failures and persistent bacteremia have been reported with chloramphenicol, and successful treatment with this drug does not appear to eliminate the patient's risk for development of the eruptive phase.
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By detecting sub-atomic particles called muons as they passed through the volcano after arriving from space, the scientists were able gradually to build up a picture of the interior, creating images of cavities through which lava was passing deep inside the volcano. A University of Tokyo volcano observatory is located on the mountain's east slope. Volcanic gas emissions from this volcano are measured by a Multi-Component Gas Analyzer System, which detects pre-eruptive degassing of rising magmas, improving prediction of volcanic activity.
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Relief map The geologic features of this active volcano are closely monitored with seismographs and strategically positioned video cameras. VolcanoLive.com: Asama Scientists have noted a range of textural variety in the ash which has been deposited in the region during the serial eruptions since the Tennin eruption of 1108.Yasui, Maya, Takahashi Masaki, and Sakagami Masakuki. "Textural Variety in the Eruptive Products of Vulcanian Eruptions between 1108 A.D. and 2004 A.D. on Asama-Maekake Volcano," Bulletin of the Volcanological Society of Japan (Kazan). Vol.
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Over the last 14.5 million years, the Anahim hotspot has created at least 40 volcanoes. They can be organized into three groupings: the eastern section, which comprises several small cinder cones and is the location of all modern volcanic activity; the central section, which consists of predominantly shield volcanoes; and the western section, all of which have since been reduced to remnants of eruptive breccia and high-level plutons and dike swarms. These form one of the six Neogene-Quaternary volcanic provinces in British Columbia.
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The most voluminous and most persistent eruptive center within the belt and in Canada is Level Mountain. It is a large shield volcano that covers an area of southwest of Dease Lake and north of Telegraph Creek. The broad dissected summit region consists of trachytic and rhyolitic lava domes and was considered to be dotted with several minor basaltic vents of postglacial age, although considered Holocene activity to be uncertain. The Mount Edziza volcanic complex is perhaps the most spectacular volcanic edifice in British Columbia.
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Mount McLoughlin from the Upper Klamath Lake, showing its summit cone Mount McLoughlin underwent at least three distinct eruptive phases. Early activity at Mount McLoughlin was explosive, and it yielded tephra and pyroclastic rock that built about a third of the overall volume. These eruptions also yielded lava flows, but they only occurred on the lower flanks. The northwestern flank has volcanic vents that produced lava flows responsible for inundating the Fourbit Creek valley from the base of McLoughlin, which extend up to the Big Butte Springs.
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Goat Rocks is an extinct stratovolcano in the Cascade Range, located between Mount Rainier and Mount Adams in southern Washington, in the United States. Part of the Cascade Volcanoes, it was formed by the subduction of the Juan de Fuca Plate under the western edge of the North American Plate. The volcano was active from 3.2 million years ago until eruptions ceased between 1 and 0.5 million years ago. Throughout its complex eruptive history, volcanism shifted from silicic explosive eruptions to voluminous, mafic activity.
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Dickinson convinced herself that her lack of faith caused turmoil to herself and those around her (especially people that she loved). When her niece died at the age of one from “eruptive sores”, she told herself that God took her niece away so that she would avoid distractions from her faith. This belief stood reasoning for never having children. In April 1789, Dickinson wrote, “God knew my tender make and doomed my darlings to death before they was my own for which […] I give thanks”.
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Only a small part of the ancient strombolian cone remains visible, in the south, with the rest covered by the tuff ring. The ashes of this eruptive episode spread over a large region, at least until Clermont-Ferrand. A second strombolian cone appeared then, the new Pariou one, slightly acentric to the south. It covered all southern and east-southern parts of the old Pariou which remain visible and then forms a large trachyandesite flow to the east which covers the first trachybasalt flow.
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Country rocks are fragmented and expelled in the atmosphere (together with fragments of the magma), eventually creating a deep crater, the bottom of which sits below the pre-eruptive ground surface. Estimates of the age of the crater vary from about 24,000 to about 80,000 years. The volcanic features around El Paso and vicinity are part of the Potrillo volcanic field, in the Rio Grande rift, which extends northward into Colorado. In 1975, Kilbourne Hole was designated as a National Natural Landmark by the National Park Service.
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Highest resolution image of Maui Patera, acquired by Galileo during an encounter with Io in October 1999 Maui Patera is a patera, or a complex crater with scalloped edges, on Jupiter's moon Io. It is about 38 kilometers in diameter and is located at . It is named after Māui, a Hawaiian demigod that sought fire from Mafuike. Its name was approved by the International Astronomical Union in 1979. It is located southwest of the eruptive center Maui, south of Euxine Mons, and southwest of the volcano Amirani.
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Starbuck has a natural talent for flying and is considered Galactica's best pilot, although she also is known for being an avid card player and drinker as well as for an eruptive temper. Bill Adama loves Kara despite her flaws and considers her something of a surrogate daughter. However, Starbuck and Colonel Tigh share a mutual sense of loathing, despite - or perhaps because of - their similarities. At the time of the attack on the Colonies, she was second in command of Galactica's fighter wing.
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July 28, 2009. Stephenharrisauthor.com Harris was a member of the American Academy of Religion, a fellow at the Westar Institute, a fellow of the controversial Jesus Seminar, and authored several books on religion, some of which are used in introductory university courses. He also had a strong interest in some geological topics. Harris grew up in western Washington state where the views of Mount Rainier inspired what has become a lifelong interest in the eruptive potential of the volcanoes in the Cascade Mountain range.
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Rocks of the CCVF host base- and precious metal deposits, including the volcanic diatreme at Cripple Creek, the site of a notable gold rush beginning in 1890. By 1900, more than 500 mines had been established in the Cripple Creek district, and the population exceeded 35,000. Open-pit gold mining continues today. Outcrops of Wall Mountain Tuff, one of the most widespread extrusive units of the CCVF, may be found near the town of Castle Rock, more than from the presumed eruptive source of the tuff.
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The Volcano, its eruptive products and a large mineral spring are protected in Lava Forks Provincial Park. Founded in 2001 as a Class A provincial park, this highly remote park covers an area of . Lying within its boundaries are the Lava Lakes, two lakes dammed by lava flows erupted from The Volcano. Located in asserted traditional territory of the Tahltan First Nation, Lava Forks Provincial Park provides a location to study ecological processes associated with primary succession or the establishment of vegetation after a major disturbance.
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He studied the geysers of Iceland, and wrote also on the classification of some of the eruptive rocks. His main work consisted in the systematic examination of the crystals of numerous minerals, in researches on their optical properties and on the subject of light polarization. He demonstrated the circular polarization of cinnabar.The New international encyclopaedia, Volume 6 edited by Frank Moore Colby, Talcott Williams He wrote especially on the means of determining the different feldspars, and is credited with the discovery of microcline (a triclinic potash-feldspar).
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However, according to the Volcano Hazards Program of the United States Geological Survey, the threat potential from the field is "Low/Very Low." Eruptive activity within the nearby Cascades Range is likely to resume. Deformation near the Three Sisters complex volcano suggests the presence of intrusive magma in the region, which could eventually lead to eruptions, though the intrusion appears to be currently stalled. Further magma intrusions could lead to eruptions that would create new cinder cones similar to those in the Sand Mountain Field.
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Observations of a second occulation on August 20, 2002 suggest that Pluto's atmospheric pressure has tripled, indicating a warming of about 2 °C (3.6 °F), as predicted by Hansen and Paige. The warming is "likely not connected with that of the Earth," says Jay Pasachoff. One astronomer has speculated the warming may be a result of eruptive activity, but it is more likely Pluto's temperature is heavily influenced by its elliptical orbit. It was closest to the Sun in 1989 (perihelion) and has slowly receded since.
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Made up of shield volcanoes and small stratocones, it had an irregular shape. Mount Scott, at a height of , marks the oldest visible remnant of this original cluster. Scott was the first of the composite volcanoes that created the Mazama complex, formed by a quick and active cone-building phase and becoming inactive long before the most recent eruption at Mazama. With time, eruptive activity moved to the west, creating the Applegate Peak and Garfield Peak cones on the southern flanks of the volcanic center.
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Andesite and dacite lava flows from the volcano usually have plagioclase as their major phenocryst, though augite and hypersthene are also present, the latter more abundant. Olivine form minor phenocrysts, which are found throughout lava flows from Mazama, and hornblende can be found in some andesite lava flows. Basalt and mafic andesite lava flows from Mazama and nearby eruptive vents have relatively higher amounts of olivine and lack hypersthene, and the mafic andesite deposits display textures that indicate they underwent greater mixing than andesite and dacite deposits.
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Most scientists believe that this drop in gas levels is caused by the sealing of gas passages by hardened magma. Such an event leads to increased pressure in the volcano's plumbing system and an increased chance of an explosive eruption. A multi-component gas analyzer system (Multi-GAS) is an instrument package used to take real-time high- resolution measurements of volcanic gas plumes. Multi-GAS measurements of CO2/SO2 ratios can allow detection of the pre-eruptive degassing of rising magmas, improving prediction of volcanic activity.
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At the south of Sisters Reach, there is a postglacial, basalt lava flow that lies on the eastern flank of Sitkum Butte (a cone that is older than this lava flow). The recent eruptive activity at Belknap Crater means that it is one of the youngest mafic volcanoes in the Oregon Cascades. There are about 6,500 people living within of Belknap Crater, with a population of about 362,000 within . However, most eruption hazards from basaltic volcanoes are generally restricted to within of the vent, with some exceptions.
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The volcanic cone corresponds to the cone-formed positive morphology originated from the accumulation of solid eruptive materials. Vieira & Klein presented an illustration of the Nova Iguaçu volcanic cone, of 1.7 kilometers in diameter, 250 meters in relative height, and 27° in flank angle. If so, the cone must appear prominently on the north-eastern flank of the Mendanha massif, and be easily recognized from Nova Iguaçu and neighbouring cities; however, such a cone is not seen or confirmed by topographic map and satellite images.Motoki et al.
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This is finally capped by alkalic flows late in its eruptive history, as the link between the seamount and its source of volcanism is cut by crustal movement. Some seamounts also experience a brief "rejuvenated" period after a hiatus of 1.5 to 10 million years, the flows of which are highly alkalic and produce many xenoliths. In recent years, geologists have confirmed that a number of seamounts are active undersea volcanoes; two examples are Lo‘ihi in the Hawaiian Islands and Vailulu'u in the Manu'a Group (Samoa).
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After the eruptive stage, the volcano entered an hydrothermal phase by March 2012. Extensively monitored during the years after the eruption, Tagoro has fertilised the nearby maritime area releasing a large amount of dissolved inorganic nutrients. Generically known as "submarine volcano of the island of El Hierro" until 2016, the Spanish Instituto Hidrográfico de la Marina (IHM) proceeded then to formally baptise the volcano as Tagoro, following a proposal by the , Tagoro is an amazigh word roughly meaning 'circular enclosure made of stones' or 'meeting place'.
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The lava shield is located on the big Reykjanes peninsula some 25 km south of ReykjavíkFor detailed maps of the region see eg. pp. 32 and 84 in: Þór Vigfússon: Í Árnesþingi vestanverðu. Ferðafélag Íslands Árbók 2003. Reykjavík 2003.. When travelling on the hringvegur and looking to the west, the volcano is to be seen in a broad valley between the palagonite ridges of Lambafell and Sauðadalahnúkar and behind some small cones, the Nyrðri and Syðri Eldborg, eruptive vents of the Brennisteinsfjöll volcanic system.
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Like the Udokan plateau, Jom-Bolok is a volcanic field part of the Baikal rift which has been volcanically active during the Holocene. Volcanism there may be the consequence either of passive rifting or mantle plume activity and has been ongoing since the Mesozoic. The basement of this area was heavily folded and altered during the Tertiary, which was also affected by river incision and earlier eruptive activity. During the late Pleistocene, thick glaciers formed in the Jom-Bolok valley and other adjacent valleys.
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Part of the Brennisteinsfjöll volcanic system are the Brennisteinsfjöll themselves (up on Hellisheiði), not really a mountain range, more some hills and crater rows, and the Bláfjöll mountain massif. The system includes two shield volcanoes, Heiðin há and Leitin. Among the many smaller subglacial mounds, tuyas, craters and eruptive vents are Stóra-Kóngsfell, Drottning, the Þríhnúkagígar crater trio - now famous because it is possible to see a magmatic feeder system from the inside -, and some craters named Eldborg (e.g. Eldborg í BláfjöllumEldborg í Bláfjöllum.
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Afterwards, phonolite domes were created on the exterior of the caldera. A period of calm lasting between 1 and 1.5 million years ensued, succeeded by a second major eruptive period that formed the modern Puy de Sancy, the highest peak in the Massif Central, followed by the establishment of smaller domes, dikes, and maars. The region is dotted with lakes of volcanic origin. Some are maars that have been filled with water, while others are the result of streams whose courses have been blocked by volcanic activity.
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The approved feature categories used for Io for different types of volcanic features include patera ("saucer"; volcanic depression), fluctus ("flow"; lava flow), vallis ("valley"; lava channel), and active eruptive center (location where plume activity was the first sign of volcanic activity at a particular volcano). Named mountains, plateaus, layered terrain, and shield volcanoes include the terms mons, mensa ("table"), planum, and tholus ("rotunda"), respectively. Named, bright albedo regions use the term regio. Examples of named features are Prometheus, Pan Mensa, Tvashtar Paterae, and Tsũi Goab Fluctus.
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Barva Volcano is an andesitic stratovolcano complex in central Costa Rica, 22 km north of San José, in Heredia Province. On the eastern side of the mountain it has a lake in what was the volcanic crater, called "Laguna de Barva", and in the western side it has three hills on the top which are called "Las Tres Marías". It is located in the small agricultural community of Sacramento. Barva has several eruptive centres at its summit and many parasitic cones on its flanks.
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This massive eruptive period was approximately coincident with the Permian–Triassic extinction event. The volcanic event is said to be the largest known volcanic eruption in Earth's history. Only the extreme northwest was glaciated during the Quaternary, but almost all is under exceptionally deep permafrost, and the only tree that can thrive, despite the warm summers, is the deciduous Siberian Larch (Larix sibirica) with its very shallow roots. Outside the extreme northwest, the taiga is dominant, covering a significant fraction of the entirety of Siberia.
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Submarine volcanoes are common features of the ocean floor. In shallow water, active volcanoes disclose their presence by blasting steam and rocky debris high above the ocean's surface. In the ocean's deep, the tremendous weight of the water above prevents the explosive release of steam and gases; however, they can be detected by hydrophones and discoloration of water because of volcanic gases. Pillow lava is a common eruptive product of submarine volcanoes and is characterized by thick sequences of discontinuous pillow-shaped masses which form under water.
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Lake Towada occupies the caldera of a stratovolcano still regarded as an active volcano. This volcano became active around 200,000 years ago, and through repeated eruptions and pyroclastic flows, especially 55,000 and 36,000 and 15,000 years ago, created an 11 kilometer diameter caldera with the proto-Lake Towada. From approximately 15,000 to 12,000 years ago, intermittent eruptions formed a small stratovolcano within this caldera (Mount Goshikiiwa). Intermediate eruptive activity continued and at least eight eruptions of magma occurred from 11,000 years ago to the present.
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The series of eruptions that produced the volcanic deposits at Cinder Cone were complex and are by no means completely understood. However, the new studies done by USGS scientists refute the purported accounts of an eruption in the early 1850s and confirm Diller's (1891, 1893) interpretation that Cinder Cone erupted in the latter half of the 17th century. They also suggest that the 1666 tree-ring date proposed by Finch (1937) for his "second" explosive eruption at Cinder Cone might actually date the entire eruptive sequence.
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Charles R. Bacon is an American expert in geology at the United States Geological Survey in the Volcano Hazards Team who has done a tremendous amount of work on Crater Lake National Park's geology. He earned his BS in Geology at Stanford in 1970 and his Ph.D. in Geology from University of California, Berkeley in 1975. His current research interests include physical volcanology, petrology, geochemistry, and eruptive histories of calderas, emphasizing detailed study of Crater Lake, Oregon, and Veniaminof and Aniakchak calderas, Alaska Peninsula.
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Anja Scheffers and Dieter Kelletat (2005), p.6 This promontory of "high" beaches is the extreme western immersion of the ancient eruptive Sintra massif, as evident from the rose- coloured granite in the north and syenite of the Ribeira do Louriçal in the south. In the vicinity of the Cape, there are geomorphological examples of gabbro-diorite, volcanic breccia, and granite. Part of the granite formations show evidence of strong coastal erosion, while in other areas there are limestone deposits embedded in the granite.
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Kīlauea's eruptive history has been a long and active one; its name means "spewing" or "much spreading" in the Hawaiian language, referring to its frequent outpouring of lava. The earliest lavas from the volcano date back to its submarine preshield stage, samples having been recovered by remotely operated underwater vehicles from its submerged slopes; samples of other flows have been recovered as core samples. Lavas younger than 1,000 years cover 90 percent of the volcano's surface. The oldest exposed lavas date back 2,800 years.
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This object is a massive Be star with a stellar classification of B2Ve. The 'e' suffix indicates the spectrum of the star displays emission lines, which are created by materials ejected from the equatorial region of this rapidly rotating star. It is classified as an eruptive Gamma Cassiopeiae variable and has been measured ranging in brightness from visual magnitude 5.34 down to 5.60. The star is an estimated 5 million years old with 8.8 times the mass of the Sun and about 4.5 times the Sun's radius.
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Between May and November 1997 this activity increased markedly, with SOSUS recording 5 such swarms, culminating with a massive 11-day, 8247-quake event around the time of the eruption, in January 1998. The seismicity began at the summit, but within 6 hours had begun to migrate south as well; by 29 November 1997 the swarm had moved south by . This coincided with lava release along the summit and southern flank. The seamount remained absolutely quiet thereafter, suggesting the completion of an eruptive cycle at the volcano.
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The Cobb hotspot has created an underwater mountain range that extends to the northwest and ends at the Aleutian Trench. The oldest mount in the chain is the Marchland Seamount, at 30 to 43 Ma (million years old). The old, northwestern end of the chain collides with a subduction zone; therefore, the true age of the hotspot is difficult to determine as the oceanic crust is being consumed. Axial Seamount is the hotspot's most recent eruptive center, which last erupted in 2015, 2011 and 1998.
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Lascar is the most active volcano in the Andean Central Volcanic Zone, and a steady pattern of eruptive activity has persisted for centuries. The volcano persistently features a tall plume of water and sulfur dioxide. Most present-day activity consists of the release of fumarolic gas with additional vulcanian activity that generates eruption columns several kilometres high, typically every three or two years, as well as active deformation of the three active craters observed in interferometric synthetic-aperture radar. The long-term magma supply rate of Lascar is about .
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25 Orionis is the dominant member of a rich low-mass star region, first identified in 2005 in a statistical analysis of 2.5 million star. It is one of several sub-associations within Orion OB1a, all thought to lie at around the same distance of 338 parsecs. Over 200 members of the 25 Orionis stellar group have been found, mostly T Tauri stars with spectral types of K and M and masses less than half the sun's. There are also around 60 hotter stars in the region, including the eruptive variable V346 Tauri.
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The outward expansion of solar ejecta into interplanetary space provides overdensities of plasma that are efficient at scattering high-energy cosmic rays entering the solar system from elsewhere in the galaxy. The frequency of solar eruptive events is modulated by the cycle, changing the degree of cosmic ray scattering in the outer solar system accordingly. As a consequence, the cosmic ray flux in the inner Solar System is anticorrelated with the overall level of solar activity. This anticorrelation is clearly detected in cosmic ray flux measurements at the Earth's surface.
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The most recent eruptive activity at Muria produced three maars on the SE and NE flanks and a lava flow from a SE-flank vent that entered one of the maars. Mount Muria or Gunung Muria is a dormant volcano on the north coast of Java, Indonesia. It is located in the center of the Muria peninsula, which juts northward into the Java Sea on the north coast of Central Java, Indonesia east of Semarang, the capital of the province. Mount Muria is 1602 meters high but once was maybe twice that height.
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Republic Graben geologic map, Washington The Republic Graben, named after the town of Republic, Washington, is one of a number of Eocene extensional basins in what is now the Okanogan Highlands. Having been down dropped it preserves a thick section of volcanic and minor volcaniclastic rocks (Sanpoil Volcanics, mainly rhyodacite) as well as fossiliferous lacustrine deposits. The volcanic rocks represent the eruptive cover of the widespread Eocene granitic intrusions in the region, and formerly must have been much more widespread. Base and precious metal deposits are widespread in the graben.
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Among other findings, this effort detected a major fault trending north-to-west under Montserrat's western side. Voight still oversees hazard assessments at the volcano, providing his input during eruptive periods in 2006 and 2010. With his students, Voight has analyzed pyroclastic flows, volcanically induced seismicity, volcanic debris avalanches, and volcanic eruption prediction. Voight has also served as a consultant geotechnical engineer for dams, tunnels, and nuclear power plants, helping plan engineering projects in France, India, Ireland, Somalia, Papua New Guinea, Canada, and Turkey, as well as in the United States.
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It was formed by volcanic eruptions that thawed through the Cordilleran Ice Sheet. The lava capping The Table was extruded after the volcano was built above lake level. Absence of glacial erratics on its summit and lack of erosional features attributable to glaciation indicates that The Table was formed by subglacial eruptions during the Early Holocene time, just prior to the disappearance of the ice sheet. Cinder Cone, a volcanic cone composed of ash, lapilli and scattered ropy and breadcrusted bomb fragments, was constructed during two periods of eruptive activity.
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These valleys, which form two major divisions, are a result of three separate eruptive events which laid down three closely spaced basalt ridges which combine to form the main section of the Preakness Range on the northern end of Second Watchung Mountain.USGS Mineral Resources On-Line Spatial Data – Preakness Basalt These ridges decrease in height from east to west, which mirrors the order in which the ridges, really successive sheets of lava, were formed. Here, as in the rest of the Watchungs, the easternmost ridge was extruded first.Nelson Horatio Darton.
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Subsequent activity 750,000 to 400,000 years ago constructed rhyolite, dacite and andesite lava domes, breccia and lava flows. Mount Silverthrone, a volcanic peak associated with the Silverthrone Caldera, consists of overlapping andesite and rhyolite lava domes that were formed during this eruptive period. The third phase, less than 1,000 years ago, produced cinder cones, pyroclastic deposits and basaltic andesite lava flows that issued from vents on the rim of the caldera. Most of this activity occurred on the northern rim where lava flows traveled down the Pashleth Creek valley then into the Machmell River valley.
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On a broader scale, the intrusive and eruptive rocks are part of the Coast Plutonic Complex, which is the single largest contiguous granite outcropping in North America. The intrusive and metamorphic rocks extend approximately along the coast of British Columbia, the Alaska Panhandle and southwestern Yukon. This is a remnant of a once vast volcanic arc called the Coast Range Arc that formed as a result of subduction of the Farallon and Kula Plates during the Jurassic-to-Eocene periods. In contrast, Garibaldi, Meager, Cayley and Silverthrone areas are of recent volcanic origin.
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The resultant boiling of the pressurized water results in the geyser effect of hot water and steam spraying out of the geyser's surface vent (a hydrothermal explosion). A geyser's eruptive activity may change or cease due to ongoing mineral deposition within the geyser plumbing, exchange of functions with nearby hot springs, earthquake influences, and human intervention.Bryan, T.S. 1995 Like many other natural phenomena, geysers are not unique to planet Earth. Jet-like eruptions, often referred to as cryogeysers, have been observed on several of the moons of the outer solar system.
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Before 2008, little was known about the eruptive history or probability of future eruptions on Kasatochi Island. There were no monitoring devices on the island, but devices on two nearby islands had indicated detectable seismic activity on Kasatochi for several years. Because of the lack of necessary technology, predicting the following eruption would have been an extremely unlikely feat. Thus, it happened quite rapidly and without much warning. On 7 August 2008, Kasatochi began erupting explosively with an ash plume maintaining an altitude of 35,000 feet and reaching 45,000 feet.
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In 1846 and in 1852, he published editions of Cazenave and Schedel on Diseases of the Skin, and in 1851 edited Gregory on Eruptive Fevers. Dr. Bulkley visited Europe for his health in June 1871, returnIng much benefited in October. He died of pneumonia at his residence in N. Y. City, January 4, 1872, after an illness of four days. In 1835 he married Juliana, daughter of Wheeler Barnes, Esq, of Rome, N. Y. He had four daughters and two sons; his widow survived him, with two daughters, and both sons.
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This indicates that an eruption in the foreseeable future is more likely to be characterized by fluid lava rather than major explosivity. However, the majority of these effusive eruptions occur in the Northern Cordilleran Volcanic Province of northwestern British Columbia and central Yukon, which is the most active volcanic zone in Canada. In the Garibaldi Volcanic Belt, eruptions occur less often, but it is the site of Canada's most explosive volcanism. The change in eruptive style between the two volcanic zones is caused by the different tectonic processes that formed them.
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Post-eruptive loops in the wake of a solar flare, image taken by the TRACE satellite (photo by NASA) A solar particle event or solar proton event (SPE), or prompt proton event, occurs when particles (mostly protons) emitted by the Sun become accelerated either close to the Sun during a flare or in interplanetary space by coronal mass ejection shocks. The events can include other nuclei such as helium ions and HZE ions. These particles cause multiple effects. They can penetrate the Earth's magnetic field and cause ionization in the ionosphere.
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Josif’s distinctive artistic sensibility is also displayed in his writings about music. By commenting pieces of music, composers’ opuses, concert performances and achievements of famous musical interpreters, Josif always marked the significance of complete entering, immersing in a piece of art. He compared the musical contexture stratification with the complexity of human being itself and defined the "tone revelation of secrets of infinity in formation and development" as the sublime purpose of musical art. He used a rich, eruptive language with many unusual and new words by his own.
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Other igneous rocks such as phonotephrite are present in smaller quantities; these occur in the Satah Mountain volcanic field. Volcanic eruptions in the last 0.33 million years have been mainly basanitic and have occurred at the youngest eruptive centre, Nazko Cone. Basanites produced by these eruptions are significantly more undersaturated than basalts from older Anahim volcanoes in the west and may indicate an eastward shift toward a deeper or less depleted mantle source. It is also possible that as the North American Plate moves over the Anahim hotspot, it underlies thinner continental crust.
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Both volcanic (eruptive) and plutonic (intrusive) igneous processes can have important impacts on geomorphology. The action of volcanoes tends to rejuvenize landscapes, covering the old land surface with lava and tephra, releasing pyroclastic material and forcing rivers through new paths. The cones built by eruptions also build substantial new topography, which can be acted upon by other surface processes. Plutonic rocks intruding then solidifying at depth can cause both uplift or subsidence of the surface, depending on whether the new material is denser or less dense than the rock it displaces.
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The volcanism that originated Facho was submarine in nature, with two visible centres positioned in the southern part of the island: Pico do Facho and a second pyroclastic cone situated west of Rocha Alta (the remains of its chamber still visible along the coast). Both these emission centre were responsible for pyroclastic and submarine lava flows. In the northern coast, there was likely another eruptive centre associated within this volcanic unit, but erosion makes its localization difficult. Following a long period of volcanic activity, conditions changed, allowing the deposition of sediments and formation of beaches.
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Other lava flows from earlier eruptions reach at least from the base of the mountain, a number of which run along the Oregon Route 140 highway. One ʻaʻā stream that filled a river valley for in length moved from an elevation of to , though it was thin, with more than of its length being less than in width. A second eruptive stage was characterized by large lava flows, which covered the inner pyroclastic core with basaltic andesite. These thin lava flows formed a shell around the loosely compacted pyroclastic interior.
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The post-collapse lava flows have been affected by glacial activity, indicating that eruptive activity ceased before the end of the last glacial stage; thus the volcano was largely constructed in pre-Holocene times. However, a long and wide lava flow extending from the youngest summit lava dome appears to post-date glaciation, and the dome itself is also unmodified. An uncertain report of an eruption on 3 December 1903 exists, as well as on 8 October 1927. Increased fumarolic activity was observed in 1854, 1888, 1889, and 1960.
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Eruptive activity at Mentolat has been ongoing since the Pleistocene, several 35,600 and 34,200 years old tephra layers in Laguna Potrok Aike may be linked to Mentolat and other explosive eruptions took place over 17,340 years ago. An eruption during the late Glacial formed the MENo tephra and another eruption 11,700 years ago produced about of tephra. The volcanic activity has been inferred from tephra layers in lakes and outcrops, about 13 eruptions have been identified with the help of tephrochronology. A major eruption of Mentolat occurred during the Holocene.
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The entire lava cone could have been constructed in about 300 years at its present rate of lava production. Eruptive activity at Bagana is frequent and is characterized by non-explosive effusion of viscous lava that maintains a small lava dome in the summit crater, although explosive activity occasionally producing pyroclastic flows also occurs. Lava flows form dramatic, freshly preserved tongue-shaped lobes up to 50-m-thick with prominent levees that descend the volcano's flanks on all sides. Just north-east of Bagana is the volcano crater lake Billy Mitchell.
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Future eruptions may include pyroclastic flows and surges similar to those that occurred at Mount Pelée, Merapi, Vesuvius, Etna, the Soufrière Hills, Mount Unzen and elsewhere. During 2003, there was an increase in seismic activity at the volcano and a rift opened on the north-east flank. No eruptive activity occurred but a quantity of material, possibly liquid, was emplaced into the edifice and is estimated to have a volume of ~1011 m3. Such activity can indicate that magma is rising into the edifice, but is not always a precursor to an eruption.
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A study conducted in 2001 determined that Tangkuban Perahu has erupted at least 30 times in the previous 40,750 years. Studies of the tephra layers within three kilometres of the crater revealed that 21 were minor eruptions and the remaining were significant eruptions. The eruptions that occurred prior to approximately 10,000 years ago were magmatic/phreatomagmatic, and the ones that occurred after 10,000 years ago were phreatic.Kartadinata, Okuno, Nakamura & Kobayashi, Eruptive History of Tangkuban Perahu Volcano, West Java, Indonesia : A Preliminary Report , Journal of Geography, 2001 The volcano erupted as recently as 26 July 2019.
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The northwest (N40W) fissure has been the most active recently, with such significant eruptive events, such as the Loma Caldera eruption which buried the ancient village of Ceren and the eruption of El Playon (1658–71) which buried the town of Nexapa. The citizens relocated to Nejapa and nowadays the eruption is celebrated annually. The most recent eruption in 1917 caused a flank eruption on the volcano along the N40W fissure. During this eruption, the crater lake inside the Boquerón evaporated and a cinder cone appeared, christened 'Boqueróncito'.
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The incubation period in human cases remains unknown, but in a person who underwent voluntary inoculation, erythema and central thickening appear by the fourth day. Most patients present a mild pre- eruptive fever that lasts 3–4 days, severe headaches and backaches, and often itching at the site where the skin lesion develops. There is initially a small nodule, without any central abrasion. This small nodule soon becomes papular and gradually enlarges to reach a maximum diameter of about 15 mm by the end of the second week of infection.
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Some evidence suggested a historical age for one of the southern lava flows, with earlier radiocarbon dating yielding an age of 330–480 years. Several chronological data imply that the lava flow was formed during two separate eruptive episodes, one 20,000 years ago and the other 11,500 - 13,000 years ago. The lava flow was probably laid down in less than a week of time, and the growth of the cone was influenced by wind, which transported tephra east-southeastwards where it fell out and formed a tephra blanket.
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After 150 years of non-eruptive activity, vegetation has grown on the surface of the lava flows, including mosses and lichens. Western Hemlock, Mountain Hemlock and Alpine tundra biogeoclimatic subzones also occur in the area, which form part of the Boundary Ranges Ecosection. Like other Iskut-Unuk River Cones, The Volcano is not monitored closely enough by the Geological Survey of Canada to ascertain how active its magma system is. This is partly because it is located in a remote region and no major eruptions have occurred in Canada in the past few hundred years.
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Fountains continued to migrate eastward along the northeast rift zone, but by dawn eruptive activity was largely restricted to echelon vents near the northeast rift zone at elevation. A voluminous a'a flow moved about down the north flank of Mauna Loa and threatened to cut the paved access road and powerlines to the Mauna Loa Observatory. At about 07:15 HST, fountains feeding this a'a flow subsided and it soon stopped about from the observatory road, having traveled . Fountaining continued at greatly diminished levels throughout the day, but ceased by nightfall.
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Segula is made up of overlapping strata of lava flows and pyroclastic deposits, built up from the caldera. Largely built of eruptive material, the stratovolcano is conical and marked by a fissure. Since it is surrounded by lava flows on the north flank and a cinder cone on the other, the mountain's caldera, or main crater, appears tiny and is therefore very difficult to make out from any photographs. The north side of the island is summarized by sharp cliffs and a shallow reef which together make accessibility from that side difficult.
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When the eruption is sufficiently strong (with sulfur dioxide reaching the stratosphere) sunlight can be partially blocked for a couple of years, with a temperature signal lasting about twice as long. In the industrial era, volcanic activity has had negligible impacts on global temperature change trends. Present-day volcanic CO2 emissions during eruptions and during non-eruptive periods represent only about 1% of current anthropogenic CO2 emissions. Physical climate models are unable to reproduce the rapid warming observed in recent decades when taking into account only variations in solar output and volcanic activity.
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Season 3 of Ice Road Truckers covers the Dalton Highway, which connects Fairbanks, Alaska, Coldfoot, Alaska, and Deadhorse, Alaska near Prudhoe Bay, Alaska, as well as ice roads constructed over the Arctic Ocean in the Prudhoe Bay area. The tagline for the season is: "In the Dark Heart of Alaska, there's a road where hell has frozen over". In this season the 2009 Mount Redoubt eruptive activity caused complications; the truckers had to carry many loads which were intended for flight, but the planes could not fly because of volcanic ash in the air.
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A series of pillow lavas were also deposited during this eruptive period. The most recent volcanic activity in the Bridge River volcanic field produced a series of basaltic lava flows in the regional valleys that overlie till of the last glacial period. The age of these valley-filling lava flows is unknown but the presence of unconsolidated glacial till under the flows suggests that they are less than 1,500 years old. To the northwest, the Franklin Glacier Complex is a set of volcanic bedrock that encompasses an area long and wide.
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Gareloi has an extensive eruptive history, dating back to at least 1760. At least 12 eruptions have occurred at the summit, accompanied by lava and pyroclastic flows. Typically they have been characterized by a central vent eruption followed by an explosive eruption, and sometimes a phreatic explosion. All have been of Volcanic Explosivity Index (VEI) of 1 to 3. Such eruptions have occurred in 1790, 1791, 1792, 1873, 1922, April 1929, 1950, January 17, 1952, August 7, 1980, January 15, 1982, September 4, 1987, and August 17, 1989.
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Rhyolitic magmas generally produce finer grained material compared to basaltic magmas, due to the higher viscosity and therefore explosivity. The proportions of fine ash are higher for silicic explosive eruptions, probably because vesicle size in the pre-eruptive magma is smaller than those in mafic magmas. There is good evidence that pyroclastic flows produce high proportions of fine ash by communition and it is likely that this process also occurs inside volcanic conduits and would be most efficient when the magma fragmentation surface is well below the summit crater.
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Pahvant Butte, May 2015 Part of the Black Rock Desert volcanic field of the Pleistocene-Holocene age, Pahvant Butte formed above older pahoehoe and aa lavas of the Pahvant field. The volcano was originally a subaqueous volcano formed under Lake Bonneville by a large eruption about 15,500 years ago. The water depth at the time of eruption is estimated to have been . This eruptive activity probably ejected steam, ash, and other materials out of the lake, enveloping the surrounding area with ash and spawning large waves in the lake.
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With an estimated original volume of approximately , the Flat Landing Brook Formation incorporates the eruptive products of a supervolcano similar in size and eruption rates to the Taupo and Yellowstone calderas. It may also represent the largest supervolcanic eruption of the Paleozoic era. Most of the volcanic rocks were laid down during a timespan of possibly less than two million years. A region of coarse co-ignimbritic breccias in the Flat Landing Brook Formation (Grants Lake pyroclastics) is interpreted to represent the infill of a large caldera with a radius of about .
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She is noted for wide-ranging contributions to the study of eruptive phenomena in the solar corona, beginning with the Solar and Heliospheric Observatory mission in the 1990s. Early work included EUV imaging studies of coronal mass ejections (CMEs) and their aftermath, including discovery of a global coronal wave response to the launch of CMEs ("EIT waves"). The majority of Thompson's solar research focuses on the study of coronal mass ejections and the dynamics of coronal structures. Her refereed publications often involve either CMEs or eruption-associated phenomena, such as dimmings and EUV waves.
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The eruption was one of several postglacial mafic events in the area, which are more common in the Sisters Reach than anywhere in the Cascade arc. It was part of a pulse of more than a dozen mafic eruptions during the late Holocene epoch in the McKenzie and Santiam Passes region between 4,500 and 1,100 years ago. Isopach mapping of the deposits from Blue Lake Crater suggest an eruptive volume of . The eruption was predominantly fed by magma and produced thick scoria fall, which overlies phreatomagmatic surge deposits with thicknesses up to .
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The grain size for the pyroclastic deposits is finest in the base surge deposits, increasing as it moves away from the base. Lithic and dense clast fragments are most common near the base of the deposit, with vesicular scoria upsection. The transition from a glassier matrix in early-stage eruptive material to a more microcrystalline character indicates that there was quenching of early-stage deposits with external water. This possibly suggests that the eruption began with phreatomagnetic activity but quickly became predominantly magmatic for the rest of its duration.
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Mazama Ash, including pumice up to thick as well as plagioclase, pyroxene, and hornblende crystals, can be found throughout the Diamond Peak wilderness area and represents the newest volcanic rock deposited in the region. In total, eruptive output probably totaled in volume. The volcano is older than the last glacial period that ended 11,000 years ago, but probably younger than 100,000 years. Though its lava flows show residual magnetism, the volcano does not display evidence of activity within the past 10,000 years, suggesting that it may now be extinct.
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Clear Lake encompasses near Oregon Route 126, with a shallow northern region and a deeper southern zone, which reaches a maximum depth of . Other nearby lakes include Lost Lake, Lava Lake, and Fish Lake. Fish Lake is an ephemeral lake that dries up during the summer season, formed by the damming of local water drainages by a lava flow from Sand Mountain Volcanic Field about 3,850 years ago. Local topography has influenced eruptive activity in the past, directing lava flows downhill to the west and, with wind, directing tephra to the northeast.
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These are the Central Group, Little Nash Crater, Lost Lake Group, Nash Crater, Sand Mountain Cones, and South Group. Slight variations in vent alignment within groups likely reflect the small differences in local tectonic stress fields. There is also evidence of vent reoccupation, suggested by lava deposits in close proximity at the Old Wagon Road vent and Great Spring vent eruptive units; one of the Great Spring cones buries part of an Old Wagon Road vent. There are three major geochemical groups in the field: Sand, Lost Lake, and Nash.
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It likely only occurred weeks or months before the major eruption, as Mazama's collapse formed a backward flow of lava when it cut through the Cleetwood lava, suggesting that the Cleetwood lava was still hot enough to flow and move. Tephra from the last major eruption that was emplaced atop Cleetwood deposits has been altered by heat and gas from the Cleetwood lava. Both these eruptive periods took place on the northern flank of the Mazama complex, not far from the magma chamber that produced the climactic eruption shortly after.
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Mazama Ash also has more soda, yttrium, ytterbium, and zirconium, and less silica and lime than eruptive products from Glacier Peak. and it forms finer deposits than Glacier Peak Ash. With an age between 6,000 and 7,000 years, Mazama Ash corresponds to the estimated time for Mazama's climactic eruption 6,600 years ago, identified by radiocarbon dating of wood charred by ashflows. Some of the Glacier Peak ash has been found in strata beneath Mazama Ash in Washington state and in eastern Idaho, to the southeast of Glacier Peak.
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The solar observatory Einstein Tower and Observatory for Solar Radio Astronomy were affiliated later. One part of the scientific activities concerned cosmic magnetic fields and cosmic dynamos, phenomena of turbulence, magnetic and eruptive processes on the Sun, explosive energy dissipation processes in plasmas, variable stars and stellar activity. Another part was directed to the early phases of cosmic evolution and the origin of structures in the Universe, large-scale structures up to those of superclusters and to active galaxies. In this connection special methods of image processing have been developed.
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Hogg Rock is located in Linn County, in the U. S. state of Oregon. It is close to Santiam Pass, by the Hayrick Butte tuya, another feature produced from the interaction of volcanic eruptive materials with glaciers. It is close to the Mount Jefferson Wilderness, near where Oregon Route 22 and US Highway 20 intersect with the Cascade Range at Santiam Pass, and sits next to Oregon Route 126. Hogg Rock lies about north of Collier Cone, a cinder cone at the northern side of the base of the North Sister.
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Pillow lava, a type of basalt flow that originates from lava-water interactions during submarine eruptions The most apparent lava flows at a seamount are the eruptive flows that cover their flanks, however igneous intrusions, in the forms of dikes and sills, are also an important part of seamount growth. The most common type of flow is pillow lava, named so after its distinctive shape. Less common are sheet flows, which are glassy and marginal, and indicative of larger-scale flows. Volcaniclastic sedimentary rocks dominate shallow-water seamounts.
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Sulfur is not strongly enriched during differentiation, in contrast to water, chlorine, and fluorine. The reason could be pre- or syn-eruptive degassing of a separate vapor phase, such as that postulated for the Pinatubo and Redoubt eruptions. The ultimate source for the excess volatile observed during the 1991 Pinatubo eruption is assumed to be sulfur-rich basaltic magmas underlying, and syn- eruptively intruded, into the overlying felsic magmas. The sulfur-rich trachytic and trachyandesitic magmas which underlay the rhyolitic magma at Changbaishan may have been a possible source for excess sulfur accumulation.
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A considerable amount of research has been done at Mount Baker over the past decade, and it is now among the most- studied of the Cascade volcanoes. Recent and ongoing projects include gravimetric and GPS-based geodetic monitoring, fumarole gas sampling, tephra distribution mapping, new interpretations of the Schriebers Meadow lava flow, and hazards analyses. Mapping of Carmelo and Sherman craters, and interpretations of the eruptive history, continue, as well. The Mount Baker Volcano Research Center maintains an online archive of abstracts of this work, and an extensive references list, as well as photos.
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Luckily, to date no crashes have happened because of jet aircraft flying into volcanic ash. Ashfalls are a threat to health when inhaled and is also a threat to property with enough accumulation. An accumulation of is sufficient to cause most buildings to collapse. Dense clouds of hot volcanic ash, caused by the collapse of an eruptive column or by being laterally expelled from the partial collapse of a volcanic edifice or lava dome during explosive eruptions, can generate devastating pyroclastic flows or surges, which can sweep off everything in their paths.
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The presence of mafic inclusions indicates that magma mixing occurs at Taapaca, with renewed eruptive episodes having been triggered by the injection of new andesitic magma into preexisting dacitic magma chambers. These dacitic magma chambers appear to have relatively small volumes, with little movement of the magma within the chamber except for the episodes where the chambers were heated by new magma injection. Based on geothermometry, a temperature of has been inferred for the dacites. The formation of the magma has been hypothesized to occur in several steps.
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They exhibit mantle bedding—the deposits directly overlie pre-existing topography and maintain a uniform thickness over relatively short distances. Sorting by size is more pronounced than pyroclastic surge or pyroclastic flows. Early settling of crystals and lithic fragments near an eruptive vent and of glassy fragments further away is a common trend witnessed during many eruptions. The St Vincent eruption in 1902 ejected a large eruption column which when settled near the vent contained 73% crystals, and ash deposited in Jamaica 1,600 km away consisted entirely of glass dust.
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The volcano has been active during the Pleistocene and Holocene, with major eruptions occurring 258.2 ± 48.8 ka ago, between 55.9 ka and 140 ka ago and 1570 ± 900 BP (380 ± 900 AD), which were accompanied by the formation of ignimbrites. Historical volcanic activity is less clear; an eruption in 1989 is considered unconfirmed. Plumes linked to phreatomagmatic eruptive activity were observed on 26 November 1995 and 1 September 2003. Seismic activity is also observed on Irruputuncu, and ongoing fumarolic activity releasing of has left sulfur deposits in the active crater.
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Subsequent activity of the volcano has completely filled the scarp. The lack of ground deformation during eruptive activity suggests the magma chamber of Irruputuncu may be more than deep, which may be linked to the thickness of the crust beneath the Central Andes, ranging . Irruputuncu displays vigorous fumarolic activity that occupies about half the summit crater and is visible within several . The high fumaroles have temperatures of and are composed mainly by sulfur dioxide, followed by minor amounts of hydrogen sulfide, hydrogen chloride, hydrogen fluoride, methane, nitrogen and oxygen.
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In February 2009 during her time as Minister of Justice, she once had a heated argument with the Minister of Agriculture William Ruto at a cabinet meeting as the President sat quietly, watching the sparring ministers, a source at the meeting said: "The President did not say or do anything. He just sat there quietly watching as the ministers took on each other. It was chaotic, hot and eruptive." The two ministers had been sparring in public over a period of three weeks, with Ms Karua demanding Mr Ruto's resignation over a maize scandal.
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In Trzaskowski's opinion, the individual segments do not cohere as a whole and are further hampered by the clichéd "rock phraseology" of the guitarists, who he said lack wit, harmony, and taste. Jazz critic Ian Carr thought the album "suffers from a monotony of sound" that attributed mostly to Lucas and Cosey's relentlessly eruptive guitar playing. Alongside the band's intense rhythms, Davis' trumpet sounded fatigued, dejected, and out of place to Carr. In general, he deemed the music "too non-Western in the sense of too much rhythm and not enough structure".
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Turrialba Volcano is an active volcano in central Costa Rica that has been explosively eruptive in recent years including 2016 and in January, March and April 2017. Visitors used to be able to hike down into the main crater, but increased volcanic activity in 2014-17, resulting in large clouds of volcanic ash, has caused the surrounding Turrialba Volcano National Park to close. The stratovolcano is high and is about 45 minutes from the Atlantic slope town of Turrialba. The summit has three craters, the largest of which has a diameter of .
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He considered that goblins could move within a star, and explode violently as they reach less dense regions towards the star's surface, and serve to explain eruptive phenomena, such as flare stars. This idea has never caught on. An anecdote often told of Zwicky concerns an informal experiment to see if he could reduce problems with turbulence hindering an observation session one night at Mount Wilson observatory. He told his assistant to fire a gun out through the telescope slit, in the hope it would help to smooth out the turbulence.
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Continuing St. Helens' ash fell in the western part of Yellowstone National Park by 10:15 p.m. and was seen on the ground in Denver, Colorado, the next day. In time, ash fall from this eruption was reported as far away as Minnesota and Oklahoma, and some of the ash drifted around the globe within about During the nine hours of vigorous eruptive activity, about 540,000,000 tons () of ash fell over an area of more than . The total volume of the ash before its compaction by rainfall was about .
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Volcanism is one of the fundamental processes of heat transfer from planetary interiors. By assessing the location of volcanic deposits and edifices, their volumes, and their sequences provide evidence for quantitative assessment of heat transfer in space and time. The region contains three major volcanoes which have smaller volcanic constructs built upon their flanks and summit regions: Atanua, Rhpisunt, Tuli, and Var Mons, and three coronae: Hulda, Madderakka, and Pölöznitsa. Due to the amount of flows from these major eruptive centers, there is much obscurities among the deposits.
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Volcanic pyroclastic rocks are formed by explosive eruption of lava and any rocks which are entrained within the eruptive column. This may include rocks plucked off the wall of the magma conduit, or physically picked up by the ensuing pyroclastic surge. Lavas, especially rhyolite and dacite flows, tend to form clastic volcanic rocks by a process known as autobrecciation. This occurs when the thick, nearly solid lava breaks up into blocks and these blocks are then reincorporated into the lava flow again and mixed in with the remaining liquid magma.
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The most recent eruptive episode in the history of Arsia Mons, among the youngest on Mars, involved at least 29 vents within the caldera and also eruptions on the flank aprons along the north-south axis of the volcano. This activity is thought to have extended from 200–300 Ma to 10–90 Ma ago, peaking at 150 Ma with eruption rates in the caldera of 1–8 km3 per Ma. This low recent rate contrasts with an average rate of 270 km3/Ma over the volcano's inferred entire 3400 Ma history.
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An alternative interpretation was that it was a metamorphically altered sedimentary rock, examples of which can be found nearby. Only in the 1950s and 1960s did research prove that it was a carbonatite; one of the clues was identification of the eruptive carbonatites found in the western part of the Kaiserstuhl. The carbonatite contains the niobium rich pyrochlore; attempts to mine the carbonatite rock for niobium were carried out in the middle of the 20th century, but the amount turned out to be too small to be economical.
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It forms the bedrock in the fjord areas, while the islands off the coast and some of the easternmost areas along the border with Sweden are made up of hard bedrock (usually granite). In some areas, as in Tysfjord and Sørfold, the bedrock is a mix of soft bedrock and hard granite. Much of the Lofoten mountains are of precambrian eruptive origin and 3.5 billion years old, among the oldest on earth. The youngest rock in Norway is on Andøya, also known for its fossils of dinosaurs and other life forms.
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These do not exist for volcanoes in British Columbia or elsewhere in Canada in the detail required. Mount Edziza, Coffee Crater and Tencho Glacier Other volcanic techniques, such as hazard mapping, displays a volcano's eruptive history in detail and speculates an understanding of the hazardous activity that could possibly be expected in the future. A large volcanic hazard program has never existed within the Geological Survey of Canada. The information has been collected in a lengthy, separate way from the support of several employees, such as volcanologists and other geologic scientists.
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Dacitic eruptions could produce volcanic columns of gas and ash that could threaten aircraft in the area. Moreover, the Lassen volcanic center poses threats to visitors from sudden avalanches that could be entirely unrelated to eruptive activity. Due to the threat of an avalanche from nearby Chaos Crag if volcanic activity renewed in the area or an earthquake occurred, the Visitor Center for Lassen Peak located at Manzanita Lake closed in 1974. In 1993, a rockfall with a volume of fell down Lassen Peak's northeastern flank, but no visitors were harmed.
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Approximately to the north beyond Big Rock is a sister lake named Little Chamcook Lake. The Chamcook Lake watershed serves as a potable water supply for the Atlantic Salmon Federation, the St. Andrews Biological Station, the Champlain Industrial Park, and the town of St. Andrews. The lake's red rock is feldspathic, of a brownish-red colour that weathers to brick-red, imperfectly syenitic, and showing some indications of an eruptive origin. A set of very fine petro-siliceous rocks, which are almost black, but have a perceptible purplish tinge are situated on the western shore.
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The Great Eruptive Solar Prominence of June 4, 1946 Dr. Bernard Lyot developed the first coronagraph to study the Sun's corona. Improved coronagraphs are used at the High Altitude Observatory by Dr. Walter Roberts and at the Evans Solar Facility by Dr. J. W. Evans. Dr. Donald H. Menzel was the first to use the coronagraph in America. These coronagraphs are used to film structures on the Sun called prominences and spicules which show matter flowing on the surface in structures many times the size of the Earth.
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This cyclical behavior is unique to Mauna Loa among the Hawaiian volcanoes.Lockwood J.P. (1995), "Mauna Loa eruptive history – the preliminary radiocarbon record", in Rhodes, J.M. and Lockwood, J.P. (eds.), Mauna Loa revealed: structure, composition, history, and hazards, Washington D.C., American Geophysical Union Monograph 92, pp. 81–94. Between about 7,000 and 6,000 years ago Mauna Loa was largely inactive. The cause of this cessation in activity is not known, and no known similar hiatus has been found at other Hawaiian volcanoes except for those currently in the post-shield stage.
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The Sturgeon Lake Caldera contains volcanic units that outcrop over from east to west with up to five separate, major ash flow tuff units with thickness ranging from to . The Mattabi pyroclastic flow, with a thickness in excess of and a strike length of at least , is the third and most voluminous eruptive event associated with the Sturgeon Lake Caldera. It hosts the 12-Mt Mattabi massive sulfide deposit which is interpreted to have formed on and below the seafloor, the latter through the processes of pore-space filling and replacement.
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Belknap Crater is a shield volcano in the Cascade Range in the U.S. state of Oregon. Located in Linn County, it is associated with lava fields and numerous subfeatures including the Little Belknap and South Belknap volcanic cones. It lies north of McKenzie Pass and forms part of the Mount Washington Wilderness. Belknap is not forested and most of its lava flows are not vegetated, though there is some wildlife in the area around the volcano, as well as a number of tree molds formed by its eruptive activity.
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The lack of evidence for volcano- ice interactions at the Mount Cayley massif implies that all eruptive stages most likely took place prior to glacial periods. This contrasts with many neighbouring volcanoes, which contain abundant volcanic glass and fine-scale columnar jointing from contact with ice during eruptions. Initial volcanic activity of the Mount Cayley massif 4,000,000 years ago corresponded with changes to the regional plate tectonics. This involved the separation of the Explorer and Juan de Fuca plates off the British Columbia Coast, which had some significant ramifications for regional geologic evolution.
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The next eruptive period, the Vulcan's Thumb stage, built an edifice that grew upon the southwestern slope of the ancestral Mount Cayley stratovolcano. This began with the eruption of massive dacite flows and blocky agglutinated breccias onto basement and older volcanic rocks of the Mount Cayley stage. These rocks partially form a ridge south of Wizard Peak and comprise the prominent summit ridge pinnacles of Pyroclastic Peak, including the Vulcan's Thumb. Later activity produced an overlying wide and long southwest-trending lobe of unconsolidated or poorly consolidated tephra.
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Though the Mount Cayley massif is currently quiet, it still poses potential hazards to nearby towns as well as logging and recreational areas. GSC seismic data suggest that the volcano still contains magma, indicating possible future eruptive activity and associated volcanic hazards such as landslides. An eruption scenario for the volcano was organized by GSC scientists in 2000 to show how Western Canada is vulnerable to such an event. They based the scenario on past activity in the Garibaldi Volcanic Belt and involved both explosive and effusive activity.
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Modern Mount Wrangell, built upon the remnants of a mid- Pleistocene volcano, has an eruptive history spanning from 750,000 years ago to minor phreatic eruptions in 1884.Volcanoes of North America, Wood and Kienle The shield volcano features an ice-filled caldera in diameter at the top of Wrangell's broad summit. The caldera was apparently formed by subsidence rather than large explosive eruptions. The caldera is in turn rimmed by three small craters, which often display fumarolic activity with steam plumes that can sometimes be seen from a distance.
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Boardwalks allow visitors to safely approach the thermal features, such as Grand Prismatic Spring. A subsequent caldera-forming eruption occurred about 160,000 years ago. It formed the relatively small caldera that contains the West Thumb of Yellowstone Lake. Since the last supereruption, a series of smaller eruptive cycles between 640,000 and 70,000 years ago, has nearly filled in the Yellowstone Caldera with 80 different eruptions of rhyolitic lavas such as those that can be seen at Obsidian Cliffs and basaltic lavas which can be viewed at Sheepeater Cliff.
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Lava strata are most easily seen at the Grand Canyon of the Yellowstone, where the Yellowstone River continues to carve into the ancient lava flows. The canyon is a classic V-shaped valley, indicative of river-type erosion rather than erosion caused by glaciation. Each eruption is part of an eruptive cycle that climaxes with the partial collapse of the roof of the volcano's partially emptied magma chamber. This creates a collapsed depression, called a caldera, and releases vast amounts of volcanic material, usually through fissures that ring the caldera.
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Consequently, the tuff has a bowl-like crater unfilled by scoria or lava. Except for the northwestern park, the Seongsan Ilchulbong Tuff Cone forms a steep cliff because of the resultant wave following its eruptions. Through these eruptions, Seongsan Ilchulbong Tuff Cone shows a perfect cross section from the intracrater strata to the marginal strata. Its diverse geological structures are considered to have great geological importance because they may be used to interpret not only the past volcanic activity of the Seongsan Ilchulbong Tuff Cone but also eruptive and depositional processes of hydromagmatic volcanoes worldwide.
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A major feature within the caldera is Halemaʻumaʻu, a large pit crater and one of Kīlauea's most historically active eruption centers. The crater is approximately in diameter and deep, but its form has varied widely through its eruptive history; the floor of Halemaʻumaʻu is now mostly covered by flows from its 1974 eruption. Kīlauea has two rift zones radiating from its summit, one leading out to the east, the other long and trending towards the southwest. A series of fault scarps connecting the two rift zones form the Koa'e Fault Zone.
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These observations serve to characterize eruptive behavior, identify the nature of precursory activity leading to eruption, define the processes by which different types of deposits are emplaced, and specify the hazards that could be unleashed by each kind of eruption. From direct observation of precursory signs, it is possible to anticipate eruptions. In times of volcanic unrest, observatories issue warnings and recommendations - they take on an advisory role for decision-making governmental civil defense agencies (the Federal Emergency Management Agency in the U.S.) and ideally continue producing observational data.
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Pleione and γ Cassiopeiae itself are both variable stars that have intermittent shell episodes where strong shell features appear in the spectrum and the brightness increases or decreases significantly. At other times the shell is not detectable in the spectrum, and even the emission lines may disappear. The General Catalogue of Variable Stars (GCVS) categorises γ Cassiopeiae stars as eruptive variables and describes them as rapidly-rotating B class giants or subgiants, although many of them are main sequence stars. It distinguishes them from those Be stars that only show smaller amplitude brightness variations.
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Patients can develop two clinical phases: an acute septic phase and a chronic eruptive phase associated with skin lesions. In the acute phase (also known as Oroya fever or fiebre de la Oroya), B. bacilliformis infection is a sudden, potentially life- threatening infection associated with high fever and decreased levels of circulating red blood cells (i.e., hemolytic anemia) and transient immunosuppression. B. bacilliformis is considered the most deadly species to date, with a death rate of up to 90% during the acute phase, which typically lasts two to four weeks.
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The ridge is a medium rate spreading center, moving outwards at a rate of approximately 6 centimeters per year. Tectonic activity along the ridge is monitored primarily with the U.S. Navy's Sound Surveillance System (SOSUS) array of hydrophones, allowing for real time detection of earthquakes and eruptive events. The Juan de Fuca Plate is being pushed east underneath the North American Plate, forming what is known as the Cascadia subduction zone off the coast of the Pacific Northwest. The plate does not subduct smoothly and can become 'locked' with the North American plate.
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The instrument package is portable, and its operation and data analysis are simple enough to be conducted by non-specialists. Multi-GAS instruments have been used to measure volcanic gas plumes at Mount Etna, Stromboli, Vulcano Italy, Villarrica (volcano) Chile, Masaya Volcano Nicaragua, Mount Yasur and Ambrym Vanuatu, Miyake-jima and Mount Asama Japan, Soufrière Hills Montserrat, with permanent installations at Etna and Stromboli. Multi-GAS measurements of CO2/SO2 ratios can allow detection of the pre-eruptive degassing of rising magmas, improving the prediction of volcanic activity.
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Thin interbedded sedimentary units that have silicified into impure chert mark breaks that have resulted from eruptive activity. This group ranges in age from >3547 to ~3260 Ma and is over 10 km thick. The Fig Tree Group was deposited between ~3260 and 3225 Ma. It is defined as a transitional unit of interlayered volcanic clasts and land derived sediments that were eroded from the underlying greenstone succession. The Moodies Group, post-3225 Ma, is a combination of sandstone and conglomerate originating from the erosion of the underlying greenstone unit and the uplifted plutonic rocks.
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In the fourth reading (, aliyah), God then told Moses and Aaron the ritual for cleansing a house with an eruptive plague. The owner was to tell the priest, who was to order the house cleared and then examine it. If the plague in the walls was greenish or reddish streaks deep into the wall, the priest was to close the house for seven days. If, after seven days, the plague had spread, the priest was to order the stones with the plague to be pulled out and cast outside the city.
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The Igwisi hills are formed by three tuff cones formed in the middle of the Tanzania craton. They are above the landscape with a karst morphology and craters covered with grass, on a low ridge that may be the product of early eruptive stages. The northeastern hill has two craters, one with a breach from which a long lava flow originates, probably formed when a lava lake in the crater escaped through a breach. The central volcano has a lava coulee and a tephra cone in its crater.
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Owing to the variety of volcanic landforms, the province was included in the 2010 Tentative List of UNESCO World Heritage Sites and a number of potential geosites have been identified at Payún Matrú itself. The active field is part of the backarc area of the Southern Volcanic Zone, a long volcanic arc and one of four eruptive belts in the Andes; the other three being the Northern Volcanic Zone, the Central Volcanic Zone and the Austral Volcanic Zone. Other volcanoes in the region include the Laguna del Maule, almost due west from Payún Matrú.
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Axial Seamount (also Coaxial Seamount or Axial Volcano) is a seamount and submarine volcano located on the Juan de Fuca Ridge, approximately west of Cannon Beach, Oregon. Standing high, Axial Seamount is the youngest volcano and current eruptive center of the Cobb–Eickelberg Seamount chain. Located at the center of both a geological hotspot and a mid-ocean ridge, the seamount is geologically complex, and its origins are still poorly understood. Axial Seamount is set on a long, low-lying plateau, with two large rift zones trending to the northeast and southwest of its center.
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However, a benefit-cost examination needs correct data about the hazard types, magnitudes and occurrences. These do not exist for volcanoes in British Columbia or elsewhere in Canada in the detail required. Other volcanic techniques, such as hazard mapping, displays a volcano's eruptive history in detail and speculates an understanding of the hazardous activity that could possibly be expected in the future. At present no hazard maps have been created for the Wells Gray-Clearwater volcanic field because the level of knowledge is insufficient due to its remoteness.
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The project hoped to shed light on some fundamental questions in volcanology, such as why magma repeatedly travels in the same conduits despite the solidification of magma in them at the end of each eruption, and how it can lose enough gas on its ascent to erupt effusively rather than explosively. Drilling began with test bores to assess the viability of a deep borehole. Two holes were drilled, and deep, and cores taken from these holes were used to better determine Unzen's eruptive history. One further deep borehole was drilled to test the methods to be used in the final drilling project.
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Since 1715 P Cygni has been a fifth magnitude star, with only minor fluctuations in brightness. Today it has a magnitude of 4.8, irregularly variable by a few hundredths of a magnitude on a scale of days. The visual brightness is increasing by about 0.15 magnitude per century, attributed to a slow decrease in temperature at constant luminosity. P Cygni has been called a "permanent nova" because of spectral similarities and the obvious outflow of material, and was once treated with novae as an eruptive variable; however, its behaviour is no longer thought to involve the same processes associated with true novae.
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Pip Ivan () is a peak in the Maramureș region on the Ukrainian-Romanian border, with height of 1,938 meters above sea level. Travaux du Muséum d'histoire naturelle "Gr. Antipa." 1996 The Maramures Mountains are extended from the Bistrifa Valley till the frontier, on the right bank of the Viseu river, and consist of a broad, fragmented summit, oriented South-East, North- West. From the geological viewpoint the territory is very varied, with crystalline schists at Pop-Ivan (1937 m) pierced by eruptive rocks (Toroioaga, 1930 m) or mezozoic basalts from the zone of Farcau (1957 m) and Mihailec (1918 m).
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Silverthrone is considerably younger than its nearest prominent neighbour Franklin Glacier Complex to the east-southeast. Most of the caldera's eruptive products have been heavily eroded by alpine glaciers and are now exposed in precipitous slopes extending from near sea level to elevations less than . The bulk of the complex appears to have been erupted between 100,000 and 500,000 years ago, but postglacial andesitic and basaltic andesite cones and lava flows are also present. Anomalously old potassium-argon dates of 1,000,000 and 1,100,000 years were obtained from a large lava flow at least long in the postglacial Pashleth Creek and Machmell River valleys.
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Activity waned after 2 mya, and after 1 mya and during the Holocene, activity was mostly andesitic in nature with large ignimbrites absent. Activity with composition similar to ignimbrites was limited to the eruption of lava domes and flows, interpreted as escaping from a regional sill high at depth. The APVC is still active, with recent unrest and ground inflation detected by InSAR at Uturuncu volcano starting in 1996. Research indicates that this unrest results from the intrusion of dacitic magma at or more depth and may be a prelude to caldera formation and large scale eruptive activity.
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Satellite image taken on 23 October 2011, showing the volcanic material in the sea Between 4.15 and 4.20am on 10 October 2011 the earthquake swarm changed behaviour and produced a harmonic tremor. Harmonic tremors are produced by magma movements and can indicate that an eruption has begun. That same day, patches of pale-coloured and sulphurous smelling water with dead fish were seen off the coast of La Restinga. A small submarine eruption had begun, 2 km south of La Restinga. Eruption 'jacuzzis', occasionally reaching 10-15m high above the surface of the water, were seen during the most energetic eruptive episodes.
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The complex features of this eruption are explained by rapid deposits of coarse pyroclastic ash near the vent and the subsequent flows of lava; and these events which were accompanied by a high eruption plume which generated further injections of pumice into the air.Yasui, Maya and Takehiro Koyaguchi. "Sequence and eruptive style of the 1783 eruption of Asama Volcano, central Japan: a case study of an andesitic explosive eruption generating fountain-fed lava flow, pumice fall, scoria flow and forming a cone," Journal Bulletin of Volcanology (Kasan). Vol. 66, No. 3 (March 2004). pp. 243–262.
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The 1991 eruption rated 6 on the Volcanic Explosivity Index and came some 450–500 years after the volcano's last known eruptive activity. The eruption ejected about of material, making it the largest eruption of the 20th century since that of Novarupta in 1912 and some ten times larger than the 1980 eruption of Mount St. Helens. Ejected material such as tephra fallout and pyroclastic flow deposits are much less dense than magma, and the volume of ejected material was equivalent to about of unerupted material. The former summit of the volcano was obliterated and replaced by a caldera wide.
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The rate of volcanism in the NCVP during this stage of activity increased again to per year. Dome-forming eruptions were dominant during the third eruptive stage 4.5 to 2.5 million years ago during which a magmatic lull appears to have been present throughout the NCVP. A fourth and final stage of volcanism at Level Mountain commenced in the last 2.5 million years with the formation of minor volcanic cones and lava flows. The NCVP volcanism rate has since remained relatively constant at per year with volcanism of the final stage having continued possibly in the last 10,000 years.
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The Bridge River Cones consist of small trachybasaltic and basaltic eruptive centers. Sham Hill (), a high steep-sided volcanic plug, is the oldest volcano in the field with a potassium-argon date of one million years. The plug is approximately wide and its bare glaciated surface, strewn with glacial erratics, consists of large subhorizontal columns formed within the central conduit of an eroded stratovolcano. The Salal Glacier volcanic complex (), with a potassium-argon date of 0.97 to 0.59 million years, contains subaerial tephra and thin scoriaceous flows in the upper part of the pile are surrounded by ice-ponded flows up to thick.
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The unique eruptive centre of this activity was in Pico Maloás. The second, or superior eruption, covers a great part of the eastern part of the island, resulting from sub-aerial and submarine eruptions. The periods of sub-aerial activity resulted in extensive outcroppings, lava fields, layered pyroclasts, dykes and numerous seams (approximately 230), that originated in the central relief of Cavacas until Caldeira, and passing through Pico Alto, while submarine lava flows extended into the sea in the Bay of São Lourenço, Maia and Ponta do Castelo. Both series of fissual eruptions are separated by terrestrial and marine sediments.
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In total, throughout its 150,000 years of eruptive activity, Broken Top erupted between of lava. Though most of the material that forms Broken Top's volcanic cone originated from its main vent, the edifice was also built up by auxiliary vents on its flanks and parasitic cones that surrounded the main edifice. The side vents erupted to form fissure vents, producing basalt and andesite, while the parasitic vents erupted scoria. Broken Top's volcanic crater, now in diameter, was most likely created through subsidence, which created a depression that was filled with thick basaltic andesite lava flows topped by thin lavas.
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Lava flows extended from the summit, and an ash plume high was produced. Large boulders were reportedly ejected and carried out to sea by eruptive force. The eruption had the distinction of being the only confirmed direct volcanic fatality in Alaska; a small detachment from the Eleventh Air Force was stationed on the volcano at the time, and one Sergeant Purchase left his post early in the eruption to take a walk and never returned, probably killed by mudslides. At approximately 10:20, a boat sent to search for Purchase witnessed the end of the eruption.
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Yet, running through the region are several smaller volcanic cones composed of black or red basaltic rock. The lower part of the parish developed along a planar zone that corresponds with the terminal area of basaltic fissural flows from the region of Pico da Bagacina, resulting in a gently sloping area towards the northwest. This area is occupied by relatively recent lava flows, with little evidence of pyroclastic eruptive material, translating into shallow soils and rocky covering. Towards the west and interior, the slope gradually increases, passing into a transition zone towards the cone of the Serra de Santa Bárbara.
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Since ~125 ka, all sub-aerial eruptive activity has been associated with the Cumbre Vieja with eruptions ranging over the whole ~25 kilometres long ridge. The Cumbre Vieja is known from submarine surveys to continue south of Punta de Fuencaliente (the Point of the Hot Fountain). Volcanic activity connected with the submarine extension has not been observed or recorded. Detailed geological mapping shows that the distribution and orientation of vents and feeder dykes within the volcano have shifted from a triple rift system (typical of most volcanic ocean islands) to one consisting of a single north-south rift.Carracedo, J. C; 1994.
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An expedition to the volcano revealed that a wide lava dome was growing in its crater. In January 2012, volcanologists at the University of Oregon warned that a tsunami caused by flank collapse of Anak Krakatoa was likely, as it had formed on a steep slope at an edge of the big caldera formed in 1883. A new eruptive phase was observed from June 2018, and on 15 October 2018, Anak Krakatau had a strong Strombolian to weak Vulcanian eruption that sent lava bombs into the water, with one almost hitting a nearby boat. The eruption was recorded on video.
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Unusually for RS CVn systems, the hotter star, Capella Ab, has the more active atmosphere because it is located in the Hertzsprung gap—a stage where it is changing its angular momentum and deepening its convection zone. The active atmospheres and closeness of these stars means that they are among the brightest X-ray sources in the sky. However the X-ray emission is due to stable coronal structures and not eruptive flaring activity. Coronal loops larger than the Sun and with temperatures of several million K are likely to be responsible for the majority of the X-rays.
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Lava flows were rapidly advancing to the west and southwest from the southwest rift zone vents. Aerial view of lava cascades into Lua Hou, upper southwest rift zone The eruptive fissures extended rapidly northeastward, across North Pit, and into the upper northeast rift zone at 02:25 HST. At 02:45 HST lava from the North Pit vents began cascading into another summit pit crater, Lua Poholo. By 03:15 HST, the lava fountains on the southwest rift zone and within Moku‘āweoweo were waning, and the lava flows moving to the west and southwest had stagnated.
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The state of California is located on the Pacific Ring of Fire, an area of highly active tectonic activity that includes seismicity and volcanism. Brokeoff and the other volcanoes near Lassen Peak were produced by subduction of the oceanic Juan de Fuca Plate under the North American Plate.Sinnotte, Barbara. Extent of Brokeoff Volcano shown by outline Brokeoff Volcano represents the Pleistocene component of the Lassen volcanic complex, an area of active volcanism for more than three million years. It formed during a period of eruptive activity approximately 600,000 years ago on a series of faults;Lopes and Lopes, p. 113.
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Adult mountain pine beetle Climate change and the associated changing weather patterns occurring worldwide have a direct effect on biology, population ecology, and the population of eruptive insects, such as the mountain pine beetle (MPB). This is because temperature is a factor which determines insect development and population success. Mountain Pine Beetle are a species native to Western North America. Prior to climatic and temperature changes, the mountain pine beetle predominately lived and attacked lodgepole and ponderosa pine trees at lower elevations, as the higher elevation Rocky Mountains and Cascades were too cold for their survival.
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Night view of Halemaʻumaʻu from Jaggar Museum in 2015 The main visitor center, located just within the park entrance at , includes displays and information about the features of the park. The nearby Volcano Art Center, located in the original 1877 Volcano House hotel, is listed on the National Register of Historic Places and houses historical displays and an art gallery. The Thomas A. Jaggar Museum, now closed due to damage from the 2018 eruptive events, is located a few miles west on Crater Rim Drive. The museum featured more exhibits and a close view of Kīlauea's active vent Halemaʻumaʻu.
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Earthquake and deformation data show no net accumulation, withdrawal, or significant movement of subsurface magma or pressurization as would be expected if the system was building toward a resumption of activity. , the lull in eruptive activity at Kīlauea continues and most of the park is open; however, some road segments and trails remain closed to visitors, while the Jaggar Museum of the Hawaiian Volcano Observatory is closed indefinitely. The Thurston Lava Tube (Nāhuku) was reopened to the public on February 21, 2020. Several large rockfalls were cleared and sensors were installed to monitor new cracks, along with improvements to water drainage and parking.
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The mountain with the appearance of a truncated cone, at the centre of the image, is Descabezado Grande volcano, and close to it is the pyramidal Cerro Azul. Cerro Azul is part of the South Volcanic Zone, which runs through central and western Chile and extends south to Argentina. This range includes at least nine caldera complexes, more than 70 of Chile's stratovolcanoes and volcanic fields that have been active in the Quaternary, and hundreds of minor eruptive centres. The South Volcanic Zone is the most volcanically active region in Chile, and produces around one eruption per year.
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In 2009, Governor of Oregon Ted Kulongoski signed a bill designating the Metolius River basin as an area of critical concern, preventing large-scale development on the land and protecting its wildlife. Despite having erupted at some point within the past 4,000 years, Blue Lake Crater is considered one of the least-known Holocene volcanoes in the Cascade volcanic arc. It forms a modest volcanic cone, its lake surrounded by a crescent-shaped, agglutinate ridge consisting of volcanic bombs. The northern side of Blue Lake Crater's rim collapsed during eruptive activity, while the southern wall remains intact.
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Volcanic activity in the Santiam Pass and McKenzie Pass has included eruptions of basalt and basaltic andesite lava flows from cinder cones and shield volcanoes. Most of these events occurred within the past 7,650 years after the deposition of Mazama Ash, yielding lava flows with rugged surfaces, unlike the more ancient, glaciated lava deposits that preceded them. Ash from these eruptions is also present. Three regional pulses of eruptive activity took place: the first from 4,000 to 3,000 years ago, the second from 2,900 to 2,500 years ago, and the third from 2,000 to 1,300 years ago.
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Eruptions in the last 5,000 years along the Mono–Inyo chain Multiple eruptions of silica-rich rhyolite from 40,000 to 600 years ago built the Mono Craters. Black Point, today on the north shore of Mono Lake, is a flattened volcanic cone of basaltic debris that formed under the surface of a much deeper Mono Lake about 13,300 years ago, during the most-recent glacial period. Several eruptive episodes from 1,600 to 270 years before present in Mono Lake formed Negit Island. The magma reservoir feeding the Mono Lake Volcanic Field is unrelated to the Mono Craters magma reservoir.
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Glacially eroded volcanic rubble At least four seismic events have occurred at Mount Cayley since 1985 and is the only volcano that has recorded seismic activity in the field. This suggests that the volcano still contains an active magma system, indicating the possibility of future eruptive activity. Although the available data does not allow a clear conclusion, this observation indicates that some volcanoes in the Mount Cayley field may be active, with significant potential hazards. This seismic activity correlates both with some of Canada's most youthful volcanoes and with long-lived volcanoes with a history of significant explosive activity, such as Mount Cayley.
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Also shown is the lateral ice-covered mountain ridge the volcanic field lies on. While molten rock comes closer to the surface it would most likely cause more fragmentation, triggering an explosive eruption that could produce an eruption column with an elevation of and may be sustained for 12 hours. A well-documented explosive eruption in the Garibaldi Belt with such force is the eruption of the Mount Meager massif 2,350 years ago, which deposed ash as far east as Alberta. This would endanger air traffic and would have to take another route away from the eruptive zone.
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Except for the tallest slopes of the complex, all cones have been covered with deposits from the climactic eruption at Mazama 7,700 years ago. Scientists now use the exposed contents of the caldera rim wall to investigate eruptions and mapping the eruptive history of the region. Throughout its known eruptions, Mazama has produced 43 percent rhyodacite, 42 percent andesite, 15 percent dacite, and less than 1 percent basaltic andesite. All of the rhyodacite has been produced within the past 30,000 years of activity, suggesting that regional and local distribution of compositions were not uniform over time.
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About 50,000 years ago, a vent at Mazama erupted the Watchman flow, which filled a canyon at the southwestern wall of the complex. From 50,000 to 40,000 years ago, Mazama vents continued to erupt andesite lava flows onto the northern and southwestern slopes and create dacite lava domes on the southern flanks. These domes often collapsed and produced pyroclastic flows that coursed down the southern slope of the volcano, forming deposits up to Devil's Backbone, a craggy volcanic dike that was exhumed when the volcano collapsed. Throughout its eruptive history, Mazama has produced basaltic andesite, andesite, and dacite lava.
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Cinder cone in 1943 Basaltic andesite lava rock sample from Parícutin, collected from a lava flow, erupted in October 1951, at the base of the volcano's "East Cascade" The nine-year activity of the volcano is divided into four stages, with names that come from the Purépecha language. The first phase (Quitzocho) extended from February 22 to October 18, 1943, with activity concentrated in the cracks that formed in the Cuiyusuro Valley, forming the initial cone. During this time, the ejected material was mostly lapilli and bombs. In March, the eruption became more powerful, with eruptive columns that extended for several kilometers.
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Other adverse complications included five reported cases of spinal cord injuries (e.g. migrating broken needles or needling too deeply), four brain injuries, four peripheral nerve injuries, five heart injuries, seven other organ and tissue injuries, bilateral hand edema, epithelioid granuloma, pseudolymphoma, argyria, pustules, pancytopenia, and scarring due to hot-needle technique. Adverse reactions from acupuncture, which are unusual and uncommon in typical acupuncture practice, included syncope, galactorrhoea, bilateral nystagmus, pyoderma gangrenosum, hepatotoxicity, eruptive lichen planus, and spontaneous needle migration. A 2013 systematic review found 31 cases of vascular injuries caused by acupuncture, three resulting in death.
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The volcano has been observed to be continuously active since 1972 and is the site of the Mount Erebus Volcano Observatory, run by the New Mexico Institute of Mining and Technology. Mount Erebus is currently the most active volcano in Antarctica and is the current eruptive zone of the Erebus hotspot. The volcanoes of the Victoria Land area are the most well known in Antarctica, most likely because they are the most accessible. Much of Victoria Land is mountainous, developing the eastern section of the Transantarctic Mountains, and the several scattered volcanoes include Mount Overlord and Mount Melbourne in the northern part.
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The album was delayed due to issues with the departure of vocalist Dan Nelson, and for a short period of time the re-joining of John Bush who ultimately decided not to commit to the album. The band eventually reunited with Belladonna, and finished recording in April 2011. Worship Music was positively received upon release, with critics describing it as "fresh and eruptive as ever" and qualified it as a return to form for the band. The record debuted at number 12 in the United States, their highest chart position since 1993's Sound of White Noise.
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The cone has a height of and an elliptical base with a horseshoe shape, probably caused by the breaching of the western-side of the volcano as a result of the effusion of lava flows during the last eruptive phase of Croscat. A study published in 2011 at the Journal of Volcanology and Geothermal Research revealed that the Santa Margarida Volcano and the Croscat were the product of the same eruption event 11,500 years ago, alternating phreatomagmatic activity, between water and magma, and magmatic activity. The internal structure of the cone has been exposed by mining operations.
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The motion of the Indian tectonic plate and the eruptive history of the Deccan traps show strong correlations. Based on data from marine magnetic profiles, a pulse of unusually rapid plate motion began at the same time as the first pulse of Deccan flood basalts, which is dated at 67 million years ago. The spreading rate rapidly increased and reached a maximum at the same time as the peak basaltic eruptions. The spreading rate then dropped off, with the decrease occurring around 63 million years ago, by which time the main phase of Deccan volcanism ended.
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Plinian eruption column, Hawaiian pahoehoe flows, and a lava arc from a Strombolian eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series. There are three different types of eruptions.
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The variety of volcanic deposits at Heart Peaks indicates that it has a history of producing not only fluid and passive basaltic lava flows, but also more silica-rich trachyte and rhyolitic lavas and explosive eruptions. Phreatic breccias are found at the volcano, providing evidence that phreatic eruptions have occurred at least once throughout its eruptive history. Features created by subglacial eruptions are also present. The latest volcanic phase at Heart Peaks is largely Pleistocene (between 2.5 million and 10,000 years ago) in age and late-stage Holocene (10,000 years ago to present) activity is uncertain.
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They noted that a large, solitary willow bush (Salix scouleriana) near the summit of Cinder Cone had not been destroyed by any eruptive activity. The bush is still alive and has not been altered much since. Because the willow at the summit of Cinder Cone was already mature in 1853, Diller concluded it was extremely unlikely that an eruption could have occurred there in the winter of 1850. He also noted that trees rooted in volcanic ash erupted from the cone were about 200 years old and that the oldest trees on related lava flows were about 150 years old.
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Diller believed he recognized two eruptive sequences, which each produced lava flows. However, he thought that only the older eruption was explosive, creating Cinder Cone and the ash deposits. In regard to the explosive eruption, he concluded that "Whatever may be the historical testimony as to the time of the eruption, the geologic evidence clearly demonstrates that it must have occurred long before the beginning of the present century" (before 1800). Diller therefore speculated that the explosive eruption had occurred between about 1675 and 1700 and that the younger, quiet eruption was "certainly" sometime before 1840.
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Directly after the eruption, the volcanic alert level for the island was raised to 4, but was decreased by 16:30 on the same day to level 3. No further eruptive activity occurred, and on 12 December the volcanic alert level was lowered to 2, signifying "moderate to heightened volcanic unrest." Volcanic tremor increased in the aftermath of the eruption, with small scale gas jetting and steam bursts observed on 13 December, however, the volcanic tremor level dropped that evening. Since the incident, the White Island Tours website has been edited to carry information about the emergency situation.
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In 1975, a journalist described Trekkies as "smelling of assembly-line junk food, hugely consumed; the look is of people who consume it, habitually and at length; overfed and undernourished, eruptive of skin and flaccid of form, from the merely soft to the grotesquely obese". He noted their fixation on one subject: In December 1986, Shatner hosted an episode of Saturday Night Live. In one skit, he played himself as a guest at a Star Trek convention, where the audience focuses on trivial information about the show and Shatner's personal life. The annoyed actor advises them to "get a life".
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They include rhyolitic volcanic rocks, gabbros, carbonatites and kimberlites. The rhyolitic rocks consist of lava flows and hydrothermally altered tuffaceous rocks that are part of two distinct eruptive centers, which are interpreted to be the eroded remains of two maars. According to field mapping and aeromagnetic data, the gabbroic rocks form two concentric ring dikes. The inner ring dike is about 20 m in width and lies about 3 km from the center of the Richat Structure. The outer ring dike is about 50 m in width and lies about 7 to 8 km from the center of this structure.
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Compared to larger stratovolcanoes in the Cascade volcanic arc, Mount Washington, like the rest of Oregon's Matterhorns, had a relatively short eruptive life. Several spatter cones produced basaltic andesite on the lower northeastern side of the volcano, following a fissure that reached from Washington's summit. There were no lava flows from this eruption, nor at an eruption at the nearby Blue Lake Crater, which produced volcanic material that displayed petrographic similarities to the Mount Washington splatter cone deposits. These include similar porphyritic textures with 10 to 15 percent plagioclase phenocrysts as well as similar alignments, suggesting that they erupted simultaneously.
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Fossils (Grypania) of more complex eukaryotic cells, from which all animals, plants, and fungi are built, have been found in rocks from , in China and Montana. Rocks dating from contain fossils of the Ediacara biota, organisms so large that they are likely multicelled, but very unlike any modern organism. In 1948, Preston Cloud argued that a period of "eruptive" evolution occurred in the Early Cambrian, but as recently as the 1970s, no sign was seen of how the 'relatively' modern-looking organisms of the Middle and Late Cambrian arose. Opabinia made the largest single contribution to modern interest in the Cambrian explosion.
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After midnight on 11 March, the first fissure opened up on Etna between the Monte Frumento Supino cinder cone and Piano San Leo. This wide and long fissure between elevation was accompanied by weak eruptive activity at its upper end and an intense glow on its lower end. During the afternoon of the same day, a second fissure opened and erupted lithics and ash clouds; historical records vary on the number of vents that became active. An alternative reconstruction of events envisages the development of several fissure segments between elevation, most of which underwent brief explosive and effusive eruptions.
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The mineralogy of an ignimbrite is controlled primarily by the chemistry of the source magma. The typical range of phenocrysts in ignimbrites are biotite, quartz, sanidine or other alkali feldspar, occasionally hornblende, rarely pyroxene and in the case of phonolite tuffs, the feldspathoid minerals such as nepheline and leucite. Commonly in most felsic ignimbrites the quartz polymorphs cristobalite and tridymite are usually found within the welded tuffs and breccias. In the majority of cases, it appears that these high-temperature polymorphs of quartz occurred post-eruption as part of an autogenic post- eruptive alteration in some metastable form.
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It rises from the abyssal floor about in height. A prominent south-trending ridge extends about from the summit area in the direction of Kimmei Seamount, to the southeast. The base of the guyot is similar to a "pedestal," and is composed of consolidated lavas and extinct volcanic centers of the volcano's formally active history; it is similar to structure to the pedestal found at the base of most of the other, usually larger Emperor seamounts. However, a thick carbonate cap, similar to the one covering Detroit Seamount, makes it difficult to find the exact eruptive centers.
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The next eruptive period, the Castle Creek period, began about 400 BCE, and is characterized by a change in composition of St. Helens' lava, with the addition of olivine and basalt. The pre-1980 summit cone started to form during the Castle Creek period. Significant lava flows in addition to the previously much more common fragmented and pulverized lavas and rocks (tephra) distinguished this period. Large lava flows of andesite and basalt covered parts of the mountain, including one around the year 100 BCE that traveled all the way into the Lewis and Kalama river valleys.
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By contrast, the much smaller southwestern rift has been quiet since a rifting episode in 1974, and to date, has not been involved in the current eruptive cycle at all. The southwestern rift zone's extremity is also underwater, although its submarine length is more limited. The southwestern rift zone also lacks a well-defined ridge line or a large number of pit craters, evidence that it is also geologically less active than the eastern rift zone. A prominent structure on Kīlauea's southern flank is the Hilina fault system, a highly active fault slipping vertically an average of per year along the system.
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Fogo consists of a single volcano, so the island is nearly round and about in diameter. The large summit caldera (about 10 kilometers in the north-south direction and 7 kilometers in the east-west direction) is not located in the center of the island, but rather towards its northeastern corner. The caldera is bounded by steep near-vertical fault scarps on the north, west, and south sides but is breached to the east where lava can flow to the coast. North-northeast-trending eruptive fissures opened along the western flank of Pico, which formed inside the caldera between about 1500 and 1760.
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Before and after comparison of the new gas vent. The crater overlook is circled for reference. 300px Before and after view of second explosion on April 9, 2008 At night, an incandescent glow illuminates the venting gas plume on September 21, 2008 Halemaumau was quiet for 25 years after the 1982 eruption, with eruptive activity at Kīlauea being focused on the volcano's east rift zone beginning in 1983. However, Hawaiian Volcano Observatory scientists observed a gradual increase in activity beginning in late 2007, including an increase in sulfur dioxide emissions and an increase in seismic tremor.
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Tatajachura is a stratovolcano in Chile, in the Isluga National Park. During the Pliocene and Pleistocene it erupted lava flows of andesitic composition and has a crater that opens westwards. The volcano is also the source of the Quebrada de Chiapa valley, and of an Inca ruin on the summit; human sacrifices were performed at the mountain to obtain a reliable water supply. The age of eruptive activity is unclear; while the appearance of the edifice suggests a lower Pliocene age, its position in the Precordillera and atop an older plain suggests it may be older than that.
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Nazko Cone, the volcano that was adjacent to the 2007–2008 Nazko earthquakes. The 2007–2008 Nazko earthquake swarm is one of numerous seismic events that have occurred near volcanoes in British Columbia. Volcanoes that have experienced volcanic earthquakes include the Mount Meager massif (seventeen events), Mount Cayley (four events), Mount Garibaldi (three events), Silverthrone Caldera (two events), Castle Rock (two events), Hoodoo Mountain (eight events), Crow Lagoon (four events), The Volcano (five events), and the Mount Edziza volcanic complex (eight events). Seismic data suggest that these volcanoes still contain active magma chambers, indicating possible future eruptive activity.
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Fan and Mortar's effect on the surrounding area, plus the size of their respective cones reveal that they were very active in the past. However, up until 1925, they were essentially two geysers that were very close to each other as their eruptive patterns were independent of each other and were nowhere near the power of the eruptions of today. Some time preceding 1925, the two must have been eventually become connected at some depth and they have since performed as one very large geyser. Fan Geyser was named by the Washburn–Langford–Doane Expedition of 1870.
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During the first eruptive period between 2,200,000 and 1,900,000 years ago, eruption of intermediate to felsic pyroclastic rocks occurred at the southern end of the massif. Basal breccia, perhaps from an exhumed vent, underlies andesite and tuffs, flows, lava domes and breccia of Devastator Peak. It has a maximum thickness of and overlies a high ridge of bedrock that formed between 251,000,000 and 65,500,000 years ago during the Mesozoic era. At the southwestern end of the massif, dacite with sparse phenocrysts (large and conspicuous crystals) of quartz, plagioclase and hornblende represents a thick remnant of subhorizontal lava flows.
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The AllMusic review by Ken Dryden states "Billy Hart's inspired drumming is the undercurrent of the date, pushing the younger musicians to play at the top of their respective games". JazzTimes' Thomas Conrad noted "Like a new-millennium Art Blakey, Hart leads a young sextet of hot emerging players, but the band here is edgier than the Jazz Messengers ever were. The careening, cacophonous repertoire comes from an earlier generation of free thinkers like Ornette Coleman and Sam Rivers. ...But the best thing about a recording led by Hart is the generous exposure to his volcanically eruptive, complex creative process".
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Cedar wood Metzora, Metzorah, M'tzora, Mezora, Metsora, M'tsora, Metsoro, Meṣora, or Maṣoro ( — Hebrew for "one being diseased," the ninth word, and the first distinctive word, in the parashah) is the 28th weekly Torah portion (, parashah) in the annual Jewish cycle of Torah reading and the fifth in the Book of Leviticus. The parashah deals with ritual impurity. It addresses cleansing from skin disease (, tzara'at), houses with an eruptive plague, male genital discharges, and menstruation. The parashah constitutes The parashah is made up of 4,697 Hebrew letters, 1,274 Hebrew words, 90 verses, and 159 lines in a Torah Scroll (, Sefer Torah).
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Position of Axial Seamount relative to the Juan de Fuca Ridge. Axial Seamount is the youngest volcano and current eruptive center of the Cobb–Eickelberg Seamount chain, a chain of seamounts that terminates south of Alaska. Axial lies where the chain intersects with the Juan de Fuca Ridge, approximately west of Oregon. It is a product of the Cobb hotspot, but now sits on an ocean spreading center between the Juan de Fuca Plate and the North American Plate, offset by the Blanco Fracture Zone to the south and a ridge-built triple junction to the north.
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'Turrialba Volcano National Park, or in Spanish the ' is a National Park in the Central Conservation Area of Costa Rica that encompasses the area around the Turrialba Volcano in Cartago Province. The park is currently closed due to the ongoing eruptive episodes of the volcano, most recently from October, 2015 to July, 2016. Major eruptions in the past include the years between 1864 and 1868. Volcanism increased in the park starting in 2014 and has featured ash clouds that have repeatedly impacted portions of Costa Rica with deposits of gritty soot and caused temporary closures of Juan Santamaría International Airport in the capital city of San Jose.
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Anjou has toured as a pianist, keyboardist, vibraphonist, and background vocalist for US singer-songwriter Sophie Auster, the Dot Wiggin Band, The Shaggs, Ravens and Chimes, and Oren Bloedow. She appears as a multi-instrumentalist on records by Ravens and Chimes, Elysian Fields, the Dot Wiggin Band, Michael Eaton, Okkervil River, Doyle Bramhall II, Emanuel and the Fear, Mary Bragg, and Stick Against Stone. In 2016, Anjou composed a live score for theater piece In the Eruptive Mode: Hijacked Voices of the Arab Spring, by Sulayman Al Bassam. The work premiered in Kuwait, Beirut, Tunis, and Metz, France, and was reviewed positively by French and Arab press.
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A.Belousov and M. Belousova, Eruptive process, effects and deposits of the 1996 and ancient basaltic phreatomagmatic eruptions in Karymskoye lake, Kamchatna, Russia. In Volcaniclastic sedimentation in lacustrine settings, James D. L. White, Nancy R. Riggs, Eds., Wiley-Blackwell, (2001) p. 39. The caldera lake associated with Taal Volcano, which was previously open to the East China Sea, was permanently closed by a pyroclastic dam during the 1749 eruption, and remains in equilibrium at a higher level to this day,History of Taal's activity to 1911 as described by Fr. Saderra Maso while the pyroclastic dam comprising the low rim of crater Lake Nyos in Cameroon is considered less stable.
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300x300px Significant phenomena affected Stromboli during its fifth life cycle between 13,000 and 4000 BP (Neostromboli). After the major eruptive phase ended about 7500–7000 years ago, the volcano has been affected by massive collapses, until it had reached its maximum expansion of the north sector for a period which lasted 3000 years. These were the most recent landslides which led to the formation of the Sciara del Fuoco, a steep slope formed by lava, lapillus and incandescent waste, which descends from the crater of Stromboli (750 m above sea level) to the sea. Since May 2002, Stromboli was characterized by a high explosive activity at 100m above the summit craters.
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Effects in a building after the tsunami of 2002, Stromboli.On December 30, two days after the start of the effusion phase, there was a partial collapse of one side of the volcano involved in the lava flow. The landslide event also affected submarine portions of the Sciara del Fuoco and caused a tidal wave whose maximum height was simulated around 10 m, the well-known tsunami of December 2002. The eruption lasted until the end of March, with small variations in the flow rate of lava and the positions of the eruptive mouths was accompanied by reduced or no explosive activity in the craters.
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The scar has been progressively filled with lava; at the beginning, the filling rate was high because of the entrance of lava flows into the sea and to the morphological readjustment of the slope; later on, the rate dramatically decreased when the eruption stopped. In February 2007, the scar was already filled by 40%, but then a new type of eruption occurred. The wideband seismic monitoring system of the Stromboli volcano has been active since January 2003 and was designed to detect and analyze the seismicity related to the eruptive processes taking place on the island. The network consists of 13 digital stations with broadband sensors.
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Andesite from the Lava Divide era, the first and longest eruptive period which spanned 460,000 to 296,000 years ago, probably produced a large volcanic cone, but it has now been reduced to a ridge. Lava flows made of andesite from 455,000 to 366,000 years ago were generated from a vent now buried under Mount Baker; at least two have subhorizontal columns indicating that they were settled adjacent to ice, likely from a glacier. Some of the lava flows also contain hypersthene basalt. In addition to these eruptions traced to Black Buttes, there are five lava flows in the vicinity for which geologists have failed to pinpoint the source vent.
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Volcanic activity at Mount Fee is among the oldest in the Mount Cayley volcanic field. Its volcanic rocks remain undated, but the large amount of dissection and evidence of glacial ice overriding the volcano indicates that it formed more than 75,000 years ago before the Wisconsinan Glaciation. As a result, the rocks comprising Mount Fee do not display evidence of interaction with glacial ice; the duration of volcanic events is unknown, and the exact timing of eruptive events is unknown. However, a large variety of volcanoes formed subglacially between 25,000 and 10,000 years ago in the vicinity of Mount Fee, including the lava domes of Ember Ridge to the south.
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While nineteenth century's Neo-Humanism, Classicism and Olympism assumed the ancient roots of sport, body cultural studies showed that the patterns central to modern sports – quantification, rationalisation, principle of achievement – could not be dated before the industrial culture of the eighteenth and nineteenth centuries (Eichberg 1978; Guttmann 1978). What was practiced before, were popular games, noble exercises, festivities of different character, children's games and competitions, but not sport in modern understanding. The emergence of modern sport was an eruptive innovation rather than a logical prolongation of earlier practices. As a revolution of body culture, this transformation contributed to a deeper understanding of the Industrial Revolution.
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43-56 The eruptive vent formed next to the medieval village of Tripergole on the shores of the then-much larger Lake Lucrino. The thermal bath village, which had been inhabited since ancient Roman times and was home to notable Roman-era buildings including Cicero's villa, was completely buried by ejecta from the new cinder cone. Tripergole's ruins and its important thermal springs completely disappeared under Monte Nuovo such that the exact location of the village can no longer be identified.Il Villaggio di Tripergole - archeoFlegrei (in Italian) Volcanologists feared another eruption between 1969 and 1984, when there were again earthquakes and changes in land elevations in the area.
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These lava tubes can be found at many of the lava flows that comprise the Indian Heaven volcanic field, which range from basaltic to andesitic in composition, and extend as far as from their source vents. The eruptive units from the field show normal residual magnetism, suggesting that they were all formed less than 780,000 years ago, with the exception of lava within Gifford Peak's eroded core. The volcanic field also features a number of Pleistocene subglacial volcanoes, many of which formed móbergs, flat-topped peaks generated by subglacial eruptions. These mountains, such as Crazy Hills, formed pillow-like shapes when their lava interacted with ice or meltwater.
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954 - 957. Meltwater flowed along a narrow basal glacier bed into a subglacial lake for five weeks, before being released as a sudden flood, or jökulhlaup. Although it has been proposed that subglacial volcanism may play a role in the dynamics of West Antarctic ice streams by supplying water to their base, for Iceland's Gjalp eruption, no rapid basal sliding was observed at the regional scale, with the formation of ice cauldrons over eruptive fissures due to the sudden removal of mass at the base. Research demonstrated that for warm-based glaciers, the effects of subglacial volcanic eruptions are localised, with eruptions forming deep depressions and causing jökulhlaups.
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Aqua showing the ash plume over North Atlantic at 13:30 GMT on 15 April The estimated ash cloud at 18:00 GMT on 15 April. After a short hiatus in eruptive activity, and a large increase in seismic activity 23:00 on 13 April and 1:00 on 14 April, a new set of craters opened early in the morning of 14 April 2010 under the volcano's ice-covered central summit caldera. The earthquake swarm was followed by the onset of a seismic eruption tremor. Meltwater started to emanate from the ice cap around 07:00 on 14 April and an eruption plume was observed in the early morning.
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On the island of Anafi, to the east, ash layers deep have been found, as well as pumice layers on slopes above sea level. Elsewhere in the Mediterranean are pumice deposits that could have been sent by the Thera eruption. Ash layers in cores drilled from the seabed and from lakes in Turkey, however, show that the heaviest ashfall was towards the east and northeast of Santorini. The ash found on Crete is now known to have been from a precursory phase of the eruption, some weeks or months before the main eruptive phases, and it would have had little impact on the island.
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The eruption formed a large caldera that, depending on the prevailing climate, was filled in about 740 years, forming a beautiful lake with a deep blue hue, known today as Crater Lake. The eruptive period that decapitated Mazama also laid waste to much of the greater Crater Lake area and deposited ash as far east as the northwest corner of what is now Yellowstone National Park, as far south as central Nevada, and as far north as southern British Columbia. It produced more than 150 times as much ash as the May 18, 1980 eruption of Mount St. Helens. This ash has since developed a soil type called andisol.
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The volcano originated as a stratovolcano in the Garigliano rift valley, with a group of eruptive mouths spread in a area; later an effusive activity concentrated in the central area, forming a volcanic cone some 1,800 m-high, mostly formed of tephra and accompanied by minor cones such as the Monte Ofelio at south-west. Some 400,000 years ago, the collapse of the volcano's eastern sector formed a caldera which, for some time, was occupied by a volcanic lake. A second period of volcanic activity began some 385,000 years ago with an explosive eruption, including eruptions from the former caldera. This phase continued until some 285,000 years ago.
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The Three Sisters form the centerpiece of a region of closely grouped volcanic peaks, an exception to the typical spacing between volcanoes elsewhere in the Cascades. This vicinity is among the most active volcanic areas in the Cascades and one of the most densely populated volcanic centers in the world, as well as the second largest volcanic field of silicic rock within the Quaternary Cascades. The area from the Three Sisters to Broken Top and Mount Bachelor features at least 50 eruptive vents for rhyolitic and rhyodacitic lava. East of Broken Top, the Tumalo volcanic center, an area of andesitic and mafic scoria cones, features similarly rhyolitic and rhyodacitic lava deposits.
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A field study was conducted in late 2001, and an automatic system based on thermal anomalies was implemented following eruptive events in 2005. In recent years the Alaska Volcano Observatory has made an effort to expand volcanic coverage westward along the Aleutian Arc. The biggest threat posed by an eruption from Mount Cleveland is its ash plume, which can damage sensitive electronic equipment on overflying planes. Many aircraft traveling over the North Pacific and over the Arctic come within the vicinity of such a plume; the only way to avoid damage is to reroute the flight, which delays arrival time and adds $5,500 to $6,000 in extra fuel costs.
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Initially, the dome extended towards the north side of the caldera, but following the emergence of two new vents in the south of the old dome around June 11 and a later one to the west, the expansion moved to the south, eventually blocking the drainage from the caldera floor. As of July 3, 2008, Chaitén continued to erupt, with associated seismic activity, an eruptive column of ash up to , and a growing lava dome. Whether the dome will be stable remains uncertain, and there is an ongoing risk of collapse and explosive pyroclastic eruption. In August 2008, an expedition reached the summit of Chaiten volcano.
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It was erupted subglacially under the Cordilleran Ice Sheet between 0.8 and one million years ago, depositing hyaloclastite tuffs, breccias and pillow breccias that now form the volcano. In the Boundary Ranges of northwestern British Columbia, Hoodoo Mountain began its formation at least 100,000 years ago mostly under glacial ice of the Cordilleran Ice Sheet. More than 90% of Hoodoo Mountain was formed during this eruptive period and interlayed peralkaline phonolitic and trachytic lava flows and hyaloclastites are the main volcanics comprising the volcano. On the northern flank of Hoodoo Mountain lies the smaller Little Bear Mountain, a tuya which also formed in the Pleistocene epoch.
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Numerous eruptions have occurred since the beginning of the Holocene epoch 10,000 years ago, when the vast Cordilleran Ice Sheet retreated rapidly at the end of the last glacial period. The majority of volcanic eruptions throughout the Holocene have occurred in British Columbia while fewer Holocene eruptions have occurred in Yukon. In the early Holocene epoch, volcanism at Hoodoo Mountain produced lava flows with well-preserved lava channels on its northwestern and southwestern flanks and are largely unglaciated, suggesting the last eruptive activity at Hoodoo Mountain occurred in an ice-free environment. These lava flows originated from the mountain's flat-topped summit and volcanic vents on its flanks.
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The lava domes are contained within the moat and floor of the Pastos Grandes caldera, but it may not be part of that caldera complex proper. The lava dome complex is part of the Altiplano-Puna volcanic complex, an igneous province located in the Central Andes. During the Late Miocene-Pleistocene, large ignimbrite eruptions took place covering an area of triggered by the formation of melts deep in the crust and their subsequent rise to the upper crust. Geochemical analysis led de Silva (1994) to suggest that they may be the latest eruptive cycle of the APVC, either as part of a reactivation or waning of that system.
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The term "clastogenic" refers to volcanic eruptions which cause a particular type of ejecta. : _Illustrative sentence_ : "The complex features of this eruption can be explained by rapid deposition of coarse pyroclasts near the vent and the subsequent flowage of clastogenic lavas which were accompanied by a high eruption plume generating pumice falls and/or pyroclastic flows."Yasui, Maya and Takehiro Koyaguchi. "Sequence and eruptive style of the 1783 eruption of Asama Volcano, central Japan: a case study of an andesitic explosive eruption generating fountain-fed lava flow, pumice fall, scoria flow and forming a cone," Journal Bulletin of Volcanology (Kasan). Vol. 66, No. 3 (March 2004). pp. 243-262.
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In Muenster, with a dedicated team of young researchers, she organized the Muenster Redshift Project (MRSP), a method to derive redshifts from UK Schmidt telescope objective prism plates, and the Muenster Red Sky Survey, a galaxy catalogue of the southern hemisphere, based on ESO Schmidt direct red plates. With the MRSP data, first indications of the action of the cosmological constant were found, shortly before major supernova searches established its existence without doubt. During most of her career, she also did research on novae and related eruptive stars. Exhibits arranged by her include Women in Astronomy, and Science in Exile (Smith College), as well as Kepler and his times (Muenster 1980).
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The proximal parts of the slide are covered by younger eruptive products and also by moraines, indicating that the slide was followed by at least one glacial episode. The slide lacks the hummocky topography usually found on debris avalanches but has radial ridges and grooves. Another landslide occurred during the Redondo stage on the eastern side of the main volcano into the Salar de Carcote. It has the classic hummocky topography of landslides and covers a length of and a surface area of , roughly half of the surface area of the Mount St Helens avalanche of 1980 and one-third of the surface area of the Ollagüe avalanche.
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In contrast to many maars, Blue Lake Crater has vesicular scoria with little evidence of extensive interaction with external water. Its eruption less than 3,000 years ago makes Blue Lake Crater one of the youngest volcanoes in the Cascade Range, and with the spatter cone chain nearby, it may also be the newest volcanic feature in the Santiam and McKenzie Passes region. The maar forms part of the Sisters Reach, which extends for and contains at least 466 Quaternary volcanoes. The reach is characterized by aligned vents and a high vent density, with a number of eruptive units containing rhyolite, which is rare for the Cascade arc.
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On 1 August 1831, Humphrey Fleming Senhouse, the captain of the first rate Royal Navy ship of the line HMS St Vincent claimed the Island for the British Crown and named it after Sir James Graham, the First Lord of the Admiralty. The eruptions of 1831 resulted in the island increasing in size to about . However, it was composed of loose tephra, easily eroded by wave action, and when the eruptive episode ended it rapidly subsided, disappearing beneath the waves in January 1832, before the issue of its sovereignty could be resolved. Fresh eruptions in 1863 caused the island to reappear briefly before again sinking below sea level.
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Eruptive activity in the Mount Cayley volcanic field is typical of past volcanism elsewhere in the Garibaldi Belt. Large earthquakes would occur under the volcanic field weeks to years in advance as molten rock intrudes through the Earth's rocky lithosphere. The extent of earthquakes and the local seismographs in this region would warn the Geological Survey of Canada and possibly cause an upgrade in monitoring. While molten rock breaks through the crust, the size of the volcano vulnerable to an eruption would probably swell and the area would rupture, creating much more hydrothermal activity at the regional hot springs and the formation of new springs or fumaroles.
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' He was a keen and accurate observer, and having an ardent love of nature and great physical activity, continued his field work in the highlands of Scotland with unflagging zeal to the end of his life. While examining a remarkable mass of eruptive granite at Inverfarigaig, on the shores of Loch Ness, he disturbed some loose stones by the strokes of his hammer, and caused the blocks above to fall on him, killing him instantaneously, 11 July 1877. He is buried in the south-west section of the Grange Cemetery in Edinburgh. The grave is at the west end of a central east- west avenue in that section.
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By 18 November the death toll had increased to 275. The toll had risen to 324 by 24 November and Syamsul Maarif, head of the National Disaster Mitigation Agency (BNPB) explained that the death toll had risen after a number of victims succumbed to severe burns and more bodies were found on the volcano's slopes. In the aftermath of the more intensive eruptive activities in late November, Yogyakarta's Disaster Management Agency reported that there were about 500 reported cases of eruption survivors in Sleman district suffering from minor to severe psychological problems, and about 300 cases in Magelang. By 3 December the death toll had risen to 353.
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The exact cause is not well understood; it may have been the result of the enormous weight of the tephra or the expansion of the eruptive vent. The sudden deposition of so much pumice generated pyroclastic flows that moved down the northern side of the volcano, coursing west–east from Llao Rock to Redcloud Cliff. The first of these pyroclastic flows were deposited at superheated temperatures, welding fragments and creating the Wineglass welded tuff, which consists of big blocks of orange-brown and gray rock. These emplacements can only be observed on the northern slopes; they are absent from the southern slopes of the volcano.
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These deposits have diameters between , though they are punctuated by pumice blocks with diameters of that extend as far as from Mazama's summit. Flows containing pumice coursed into the Annie Creek and Sun Creek canyons southward of Mazama, depositing of material, which have still not been fully eroded after almost 8,000 years. To the southeast, pyroclastic flows coursed into Sand Creek and extended more than in that direction, some reaching Klamath Marsh, the Williamson River, and the Klamath Lakes. Mazama's eruptive activity drew from deeper layers of the magma chamber that fed its climactic eruption, with denser layers of andesite and basaltic andesite lying beneath lighter layers of rhyodacite.
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The Geophysics Institute at the National Polytechnic School in Quito houses an international team of seismologists and volcanologists Institute for Geophysics at National Polytechnic School whose responsibility is to monitor Ecuadors numerous active volcanoes in the Andes Mountains of Ecuador and in the Galápagos Islands. Ecuador is located in the Ring of Fire where about 90% of the world's earthquakes and 81% of the world's largest earthquakes occur. The geologists study the eruptive activity for the volcanoes in the country, especially Tungurahua whose volcanic activity restarted on 19 August 1999, and several major eruptions since that period, the last starting on 1 February 2014.
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The sub-horizontal arrangement of the vein field was controlled, by pre-existing fracturing due to early deformation or by the associated stress field with the granitic intrusion mechanism. In the ascending phase of the intrusive massive, the fluid pressure is sufficiently elevated, causing a network of radial fractures to open around the eruptive centre, intruding residual granitic rocks into the fractures. In the following phase, when the pressure of the ascending magma and the resistance of the embedding rock to the intrusion are equal, there is a decrease in fluid pressure and consequently shearings, are bisected by the radial direction. The fluids modifies the interior of the granite dome – greisenisation.
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Volcanic gas emissions from this volcano are measured by a multi-component gas analyzer system, which detects pre-eruptive degassing of rising magma, improving prediction of volcanic activity. On 3 July 2019, two major explosive events occurred at around 16:46 local time, alongside 20 additional minor explosive events identified by Italy's National Institute of Geophysics and Volcanology. A hiker near the volcano's summit was killed after being struck by flying debris when the eruption began. On 28 August 2019, at 10:16 local time, an explosive eruption sent a pyroclastic flow down the volcano’s northern flank and into the sea, where it continued for several hundred meters before collapsing.
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Mount Garibaldi as seen from Squamish Explosive eruptions from Mount Garibaldi would pose a severe threat to the nearby communities of Whistler and Squamish. Although no Plinian eruptions have been identified in Garibaldi's eruptive history, even Peléan eruptions could create large amounts of ash that could significantly affect these local communities. Ash columns may rise to several hundred meters above the volcano, and due to its close proximity to Vancouver this could pose a threat for air traffic. Melting of leftover glacial ice covering the Mount Garibaldi area may cause floods, lahars, or debris flows that could possibly threaten small communities such as Brackendale.
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Originally, the Granada ignimbrite was also considered to be a product of an earlier eruption of the Vilama caldera; later research indicated that it has its own eruptive centre at Abra Granada that is unrelated to Vilama. According to this older theory of caldera history, the Granada ignimbrite was the first stage of caldera formation, with the second stage generating the Vilama ignimbrite proper. This theory also envisaged two later stages of activity, the first linked to the Cerro Morado mafic volcanics and the Salle and Ceja Grande ignimbrites, while the fourth produced the Bonanza ignimbrite from the Coruto caldera as well as additional volcanoes including Cerro Zapaleri.
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Locations of Boring vents in the Portland, Oregon area D. E. Trimble (1963) argued that the Boring Lava Field was produced by eruptive activity at 30 volcanic centers. These include shield and cinder cone volcanoes. J. E. Allen reported 95 vents in 1975, dividing them into four clusters in 1975: 17 vents north of the Columbia River, 14 vents west of the Willamette River, 19 vents east of the Willamette River and north of Powell Valley Road, and 45 vents east of the Willamette River and south of Powell Valley Road (Highway 26). Of these, 42 were unnamed, and several volcanoes contained multiple vents.
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These bodies are parts of a once-continuous mass that probably extended from San Pablo Bay northward into southern Lake County, and from Green Valley in Solano County westward to Santa Rosa Valley. The Sonoma volcanics are several thousand feet thick." "The materials composing the Sonoma volcanics were erupted probably from several vents within the area, and intermittently over a period perhaps more than 1 million years long. The materials were extremely varied in chemical composition and in eruptive character, so that they formed a complex assemblage of flows, dikes, plugs, mudflows, breccias, pumice beds, and intercalated bodies of stratified material mostly volcanic in composition but sedimentary in deposition.
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A lateral crater of the 2002–2003 eruption near the Torre del Filosofo, about below Etna's summit. House destroyed by lava on the slopes of Etna. Following six years (1995–2001) of unusually intense activity at the four summit craters of Etna, the volcano produced its first flank eruption since 1991–1993 in July–August 2001. This eruption, which involved activity from seven distinct eruptive fissures mostly on the south slope of the volcano, was well covered by the mass-media because it occurred at the height of the tourist season and numerous reporters and journalists were already in Italy to cover the G8 summit in Genoa.
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Specifically, close to the surface, the tail ends of hairpin vortices could gradually converge resulting in provoked eruptions, producing new hairpin vortices. Hence, such eruptions are a regenerative process, in which they act to create vortices near the surface and eject them out onto the outer regions of the turbulent wall. Based on the eruptive properties, such flows can be inferred to be very efficient at heat transfer because of mixing. Specifically, eruptions carry hot fluids up while cooler flows are brought downwards during the converging of tails of the hairpin vortices before erupting.Haidari, A. H., Smith, C. R. “The generation and regeneration of single hairpin vortices” J. Fluid Mech.
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Initiation of volcanism at Coso preceded the onset of Basin and Range crustal extension there, as expressed by normal faulting. The earlier of the two principal periods of volcanism began with the emplacement of basalt flows over a surface of little relief. Then, during the ensuing period of approximately 1.5 million years, eruptive activity included chemically more evolved rocks erupted upon a faulted terrain of substantial relief. Following a 1.5-million-year hiatus with few eruptions, a bimodal volcanic field of basalt lava flows and rhyolite lava domes and flows developed on Basin and Range terrain of essentially the same form as today's landscape.
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The most recent volcanic activity at the Mount Edziza volcanic complex have been hot springs, several of which are found on the volcano's western flank, including Elwyn springs (36°C or 97°F), Taweh springs (46 °C or 115 °F), and inactive springs near Mess Lake. The springs are near the youngest lava fields of the Mount Edziza volcanic complex and are most likely associated with the most recent eruptive activity. These hot springs were highly important to the adjacent Tahltan people. Hot springs are closely associated with fumaroles, which are vents in an active volcanic area releasing steam and hot gases, such as sulfur dioxide.
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Symbiotic novae are slow irregular eruptive variable stars with very slow nova-like outbursts with an amplitude of between 9 and 11 magnitudes. The symbiotic nova remains at maximum for one or a few decades, and then declines towards its original luminosity. Variables of this type are double star systems with one red giant, which probably is a Mira variable, and one white dwarf, with markedly contrasting spectra and whose proximity and mass characteristics indicate it as a symbiotic star. The red giant fills its Roche lobe so that matter is transferred to the white dwarf and accumulates until a nova-like outburst occurs, caused by ignition of thermonuclear fusion.
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Mount Washington is also part of the Sisters Reach subsegment, which extends for and contains at least 466 volcanoes that were active during the Quaternary. Washington represents one of 30 mafic (rich in magnesium and iron) stratovolcanoes and shield volcanoes in the group, which include Pleistocene and Holocene eruptive centers. The volcano and its wilderness area sit on a lava platform with an altitude of , and they are bounded by faults to the east and west. Volcanic rocks contained within the wilderness area are either composed of older basalt or younger basaltic andesite, all of which were produced during the Quaternary, probably during the past 700,000 years.
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Eruptive activity at Newberry Volcano began about 600,000 years ago and has continued into the Holocene, the last eruption taking place 1,300 years ago. Unlike other shield-shaped volcanoes, which often erupt basaltic lavas only, Newberry Volcano has also erupted andesitic and rhyolitic lavas. A popular destination for hiking, fishing, boating, and other recreational activities, the volcano lies within of 16,400 people and within of nearly 200,000 people, and it continues to pose a threat to life. Still considered an active volcano, it could erupt and produce lava flows, pyroclastic flows, lahars (volcanically induced mudslides, landslides, and debris flows), ashfall, earthquakes, avalanches, and floods.
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Mount Mazama erupted 7,700 years ago, producing volcanic ash and pumice that accumulated to a thickness of up to on the Newberry Volcano, covering many of the lava flows on its slopes. During three eruptive periods at Newberry over the past 7,500 years, the caldera has seen rhyolitic eruptions from seven individual vents. About 7,000 years ago, eruptions occurred along the rift zone northwest of Newberry Volcano's caldera, yielding 12 lava flows that encompassed an area of . At about the same time, the Central Pumice cone was produced by eruptions that also formed the Interlake and Game Hut obsidian flows from a vent on the cone's southern flank.
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They erupted dacite lava flows and silicic lava domes from vents east of the former central cone, and were influenced by ice on Mount Jefferson, which prevented them from diffusing across the volcano's flanks. Instead, they formed lava tongues near the crater and coursed down spaces in between glaciers, creating volcanic glass and columnar joints, or arrays of prismatic shapes. Silicic lava domes from this eruptive episode collapsed over and over again, producing block-and-ash flows, or pyroclastic flows with many volcanic blocks among ash with a similar composition. About 150,000 years ago, an eruption produced the volcanic rock in the Park Butte area.
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Royal Navy Commander George Vancouver and the officers of HMS Discovery made the Europeans' first recorded sighting of Mount St. Helens on 19 May 1792, while surveying the northern Pacific Ocean coast. Vancouver named the mountain for British diplomat Alleyne Fitzherbert, 1st Baron St Helens on 20 October 1792, as it came into view when the Discovery passed into the mouth of the Columbia River. Years later, explorers, traders, and missionaries heard reports of an erupting volcano in the area. Geologists and historians determined much later that the eruption took place in 1800, marking the beginning of the 57 year-long Goat Rocks Eruptive Period (see geology section).
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The Emeishan Traps are associated with the end-Guadalupian extinction or end-Capitanian extinction event, the extinction of animal and plant life that occurred at the end of the Capitanian stage of the Guadalupian epoch of the Permian period. Limestone within the traps show the extinction to occur immediately below the first eruptive unit, with the mass extinction marked at the onset of explosive Emeishan volcanism. The formation of volcaniclastics suggest violent phreatomagmatic-style eruptions. The synchrony between the Emeishan Traps and the end-Guadalupian extinction has been taken to support the argument of Vincent Courtillot and others, that volcanism is the main driver of mass extinctions.
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Perhaps as a mark of the island's relative isolation, only one eruption has ever been recorded on the island, from the Volcan de Lomo Negro vent of Tanganasoga in 1793. The eruption lasted a month. It is considered that the 2011-2012 El Hierro eruption at La Restinga in the southernmost part of the island is a vent of Tanganasoga. Swift deformation of Tanganasoga was recorded during the October 2011-March 2012 eruptive phase of this volcanic activity, and in June 2012 a new phase was heralded by earthquakes and rapid deformation upwards and outwards of Tanganasoga, indicating the deep-seated movement of magma below.
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Some accounts of this earthquake refer to a major eruption from Etna at the time of the earthquake, blaming most of the deaths in Catania and the tsunami on the eruption. However, most later workers believe that the tsunami was triggered by the earthquake and that the only effect on Etna was the collapse of part of the cone above Taormina, with no significant eruption. As with the 1693 earthquake the 1169 event seems to have followed after a major period of eruptive activity. Calculations have shown that a major eruption may significantly increase the stress on the normal faults to the south-east of the volcano.
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The solar magnetic field structures the corona, giving it its characteristic shape visible at times of solar eclipses. Complex coronal magnetic field structures evolve in response to fluid motions at the solar surface, and emergence of magnetic flux produced by dynamo action in the solar interior. For reasons not yet understood in detail, sometimes these structures lose stability, leading to coronal mass ejections into interplanetary space, or flares, caused by sudden localized release of magnetic energy driving emission of ultraviolet and X-ray radiation as well as energetic particles. These eruptive phenomena can have a significant impact on Earth's upper atmosphere and space environment, and are the primary drivers of what is now called space weather.
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Tofua's pre-caldera activity is recorded by a sequence of pyroclastic deposits and lavas constituting the older cone, followed on the northern part of the island by froth lavas or welded and unwelded ignimbrite. Following the caldera collapse, lavas were erupted from the northern part of the island and the caldera-rim fissure zone, scoria and lavas from the caldera-wall fissure zones, pyroclastics and lavas from intracaldera cones, and recent pyroclastic fall deposits on the outer cone. Eruptive products are mainly basaltic andesites and andesites, plus occasional dacite flows within the older cone. A postcaldera cone with fumarolic activity (Lofia) is in the northern part of the caldera; a crater lake with depth occupies most of the remainder.
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In November the level of the lava located in the craters was very high, which resulted in an overflow in the upper part of the Sciara del Fuoco, which has increased Strombolian activity and has caused several explosions in the early December as well. The heights of ejecta were intense at Crater 1. Afterward, it reached 200m above Crater 1, and the explosions left magma closely to the crater's rim. At local time 18.30 (UTC+1) on December 28, a not usual activity characterized by a 300m long eruptive break occurred, causing the break of the northern wall of Crater 1, displacing the North West upper eastern part of the Sciara del Fuoco wall.
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Rarely, a minor eruption may occur involving about 10 to 15 seconds of hesitating, moderately low spouting and splashing. Although it is overshadowed in eruptive height and power by Great Fountain Geyser, White Dome Geyser is a significant feature that was used as an emblem by the old Yellowstone Library and Museum Association, now the Yellowstone Association. The thermophilic bacterium Thermus aquaticus, important because it produces an enzyme used in polymerase chain reaction laboratory procedures central to modern molecular biology, was first isolated from Mushroom Pool, a non-erupting hot spring a few hundred feet from White Dome Geyser. White Dome is the largest member of the White Dome Group, a cluster of features bisected by Firehole Lake Drive.
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Silverthrone is part of the Pemberton Volcanic Belt, which is circumscribed by a group of epizonal intrusions. At another deeply eroded caldera complex called Franklin Glacier Complex, the Pemberton Volcanic Belt merges with the Garibaldi Volcanic Belt, a northwest-trending belt of volcanic cones and fields extending from near the Canada–United States border east of Vancouver on the British Columbia Coast. The intrusions are thought to be subvolcanic bodies associated with a volcanic front that was active in the Miocene, during early stages of subduction of the Juan de Fuca Plate. With the notable exception of King Island, all the intrusive and eruptive rocks are calc-alkaline, mainly granodioritic bodies and dacite ejecta.
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Black Buttes was active during the mid-Pleistocene from 495,000 to 288,000 years ago, producing viscous, andesitic lava flows with a steep dip (the steepest angle of descent of a tilted bed or feature relative to a horizontal plane) that reach thicknesses of up to , though they were could actually be larger as they are covered by ice. Its most active eruptive period took place between 350,000 and 330,000 years ago. During the construction of its main edifice, at least four flank eruptions from satellite vents separate from its central crater generated lava flows. The first three eruptions produced andesitic flows, while the fourth and most recent event yielded lava composed of basaltic andesite.
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Bartonella bacilliformis is the etiologic agent of Carrion's disease or Oroya fever (acute phase of infection), and verruga peruana or Peruvian wart (chronic phase of infection). The acute phase of the disease is a life-threatening disease characterized by massive invasion of Bartonella to human red blood cells and consequently acute hemolysis and fever. If the infection is not treated, the case fatality rate is 40 to 85% Patients in this phase of the infection can be complicated by overwhelming infections, primarily by enterobacteria (Salmonella spp) and parasites (Toxoplasma gondii, Pneumocystis jirovecii). The chronic phase is characterized by benign eruptive lesions that are pruritic and bleeding, and other symptoms like malaise and osteoarticular pain.
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Homa Mountain, Kenya in 1994 An eruption of Pacaya, Guatemala in 1976 Mt. Banahaw, Luzon, Philippines in 1989 Kelimutu, Flores, Indonesia A complex volcano, also called a compound volcano, is mixed landform consisting of related volcanic centers and their associated lava flows and pyroclastic rock. They may form due to changes in eruptive habit or in the location of the principal vent area on a particular volcano. Stratovolcanoes can also form a large caldera that gets filled in by a lava dome, or else multiple small cinder cones, lava domes and craters may develop on the caldera's rim. Although a comparatively unusual type of volcano, they are widespread in the world and in geologic history.
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Beginning in 2002, the Volcán de Fuego entered a new active period, with more or less continuous activity, interspersed with monthly eruptive episodes. These episodes would typically send ash falling on communities within 20km of the volcano, and lava flows about 1-2km from the summit, and the occasional pyroclastic density current. On 3 June 2018, the volcano suddenly produced its most powerful eruption since 1974. Large pyroclastic density currents were produced that over-topped the barranca boundaries they had previously been confined to and unexpectedly hit El Rodeo, Las Lajas, San Miguel Los Lotes, and La Reunión villages in Escuintla, which buried the towns and killed many of the surprised residents.
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Krakatoa, or Krakatau (), is a caldera in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung. The caldera is part of a volcanic island group (Krakatoa Archipelago) comprising four islands: two of which, Lang and Verlaten, are remnants of a previous volcanic edifice destroyed in eruptions long before the famous 1883 eruption; another, Rakata, is the remnant of a much larger island destroyed in the 1883 eruption. In 1927, a fourth island, Anak Krakatau, or "Child of Krakatoa", emerged from the caldera formed in 1883. There has been new eruptive activity since the late 20th century, with a large collapse causing a deadly tsunami in December 2018.
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Second fissure, viewed from the north, on 2 April 2010 The first phase of the 2010 eruption began late on the evening of 20 March at the Eyjafjallajökull. The initial visual report of the eruption was at 23:52 GMT, when a red cloud was seen at the north slopes of Fimmvörðuháls mountain pass, lighting up the sky above the eruptive site. The eruption was preceded by intense seismicity and high rates of deformation in the weeks before the eruption, in association with magma recharging of the volcano. Immediately before the eruption, the depth of the seismicity had become shallow, but was not significantly enhanced from what it had been in the previous weeks.
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The Institute of Earth Sciences made a preliminary estimate of erupted material in the first three days of the eruption on 14 April 2010 at Eyjafjallajökull. The erupted products were fragmented material, the majority fine-grained airborne tephra. Eruptive products can be split into three categories along with preliminary estimated erupted volumes: # Material (tephra) in the ice cauldrons around the volcanic vents: # Tephra filling the glacial lagoon of Gígjökulslón, carried by floods down the outlet glacier Gígjökull: # Airborne tephra that was carried to the east and south of the volcano, uncompacted tephra fallout from eruption plume: Total: which corresponds to some of magma. The magma discharge rate was about or 750 t/s.
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Its epicenter was in the municipality of Rizal, Nueva Ecija, about northeast of Pinatubo, and faulted northwest-southeast through three provinces. It also followed the Philippine Fault System west as far as Baguio, which was devastated, and is located about north-northeast of Pinatubo, leading volcanologists to speculate that it might ultimately have triggered the 1991 eruption, although this is impossible to prove conclusively. Two weeks after the earthquake, local residents reported steam coming from the volcano, but scientists who visited there in response found only small rockslides rather than any pre-eruptive activity. On March 15, 1991, a succession of earthquakes were felt by villagers on the northwestern side of the volcano.
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The rift valley remained a depression in the Tyrrhenian Sea for about 2 million years and then in the Tuscolano- Artemisio phase, dated 600-360 thousand years BP, a series of volcanic changes began leading to the current land form: the first four eruptive cycles of a new volcano in the vicinity of the Monti Albani, which spread pyroclastic rock and formed a caldera. In the Campi di Annibale phase, 300-200 thousand years BP, a stratovolcano formed in the caldera. Approximately contemporaneously, in the Middle Pleistocene, 781-126 thousand years BP, beds of sand and clay, termed the Latina Complex, appeared above sea level over the outer karst, enclosing a lagoon.Van Joolen Chapter 1 2003 p. 11.
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All of the family members and servants get a coach and travel for weeks, experiencing a number of complications and set-backs. The letters come from all of the members of the entourage, and not just the patriarch or matriarch. They exhibit numerous voices, from the witty and learned Oxford University student, Jerry (who is annoyed to accompany his family), to the eruptive patriarch Matthew Bramble, to the nearly illiterate servant Wynn Jenkins (whose writing contains many malapropisms). The title character doesn't appear until over half way through the novel, and he is only a coachman who turns out to be better than his station (and is revealed to be Matt Bramble's bastard son).
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Diamond Head is part of the system of cones, vents, and their associated eruption flows that are collectively known to geologists as the Honolulu Volcanic Series, eruptions from the Koolau Volcano that took place long after the volcano formed and had gone dormant. These eruptive events created many of Oahu's well-known landmarks, including Punchbowl Crater, Hanauma Bay, Koko Head, and Mānana Island in addition to Diamond Head. Diamond Head, like the rest of the Honolulu Volcanic Series, is much younger than the main mass of the Koolau Mountain Range. While the Koolau Range is about 2.6 million years old, Diamond Head is estimated to be about 500,000 to 400,000 years old.
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There is evidence that early and middle-Holocene Sabancaya mostly erupted lava, while the late-Holocene volcano was more explosive in its activity. It is possible that the Inca performed human sacrifices in response to eruptions of Sabancaya to calm down the mountain spirits. The 1994 eruption of Sabancaya Spanish chronicles mention probable eruptions in 1752 and 1784, which might have left layers of tephra. After the 18th century, the volcano went dormant for about two hundred years during which only fumarolic activity was recorded. In late 1986 an increased fumarolic activity heralded the onset of a new eruptive period, and satellite images observed the occurrence of black spots where the ice had melted or boiled away.
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Little is known about Cleveland's early eruptive history as its remoteness makes it a difficult area to investigate, and discrepancies in names have caused confusion between events there and those on nearby Carlisle. Even today, not all possible events are confirmed as eruptions by the Alaska Volcano Observatory, and many are listed as "possible." In observed history, Mount Cleveland may have first erupted in 1744; the first confirmed eruption occurred in 1828. The volcano erupted again in 1836 (possibly), 1893, 1897 (possibly), 1929 (possibly), 1932, and 1938 (possibly). The first notable eruption from Mount Cleveland was a Volcanic Explosivity Index (VEI) 3 Vulcanian eruption that occurred between June 10 and June 13, 1944.
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Lava then flowed from the Duraznero vent and fissure, filling the adjacent crater of El Fraile and created a lava lake. This subsequently overflowed and the lava flowed down the eastern flank towards the ocean. It finally stopped about 30m (about 100 feet) from the ocean. Also later, on 30 July all eruptive activity ceased and only residual fumarolic activity continued until 4 August; thereafter there was only thermal emissions. It is estimated that approximately 60 million cubic metres of lava was erupted during the eruption.Klügel, A; Schmincke, H –U; White, J. D. L; and Hoernle, K. A; 1999. Chronology and volcanology of the 1949 multi-vent rift-zone eruption on La Palma (Canary Islands).
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Anak Krakatoa () is an island in a caldera in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung.Volcano; On December 29, 1927, Anak Krakatoa emerged from the caldera formed in 1883 by the explosive volcanic eruption that destroyed the island of Krakatoa. There has been sporadic eruptive activity at the site since the late 20th century, culminating with a large underwater collapse of the volcano which caused a deadly tsunami in December 2018, followed by subsequent activity in 2019 and an eruption in April 2020. Due to its young age, the island is one of several in the area which are of considerable interest to volcanologists, and the subject of extensive study.
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The Trindade hotspot is marked 41 on the map The Trindade hotspot is a working hypothesis supposing that the submarine volcanic chain Vitória-Trindade, off the eastern coast of Brazil in the southern Atlantic Ocean, is a volcanic hotspot chain. It was considered that the supposed hot-spot should be responsible for the creation of the east-west trending Vitória-Trindade seamount chain, which includes the Trindade and Martim Vaz archipelago at its easternmost end. Trindade, a small island in the archipelago, is the hotspot's most recent eruptive center. This ideas was based on the geochemical data, especially of the highly silica-undersaturated alkaline ultramafic rocks of the Trindade Island and Martim Vaz Island.
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Age progression is not clearly related to geographic distribution, though Blue Lake Crater and the spatter cone chain nearby mark two small eruptive centers in the eastern Santiam Pass area. Blue Lake Crater erupted at some point within the past 4,000 years. The maximum age, determined by Taylor (1965), was 3,440 ± 250 years for a tree limb between Blue Lake Crater tephra deposits and volcanic ash from Sand Mountain Volcanic Field. Scott (1977) also concludes that the evidence suggests the eruption took place 3,440 ± 250 years ago. Charred forest litter was found under cinders from the spatter cone chain near Blue Lake Crater and used to determine a minimum age of 1,330 ± 140 years.
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Panorama of Mývatn from the town of Skútustaðir, November 2007 The Hverfjall crater, immediately east of Mývatn Lava island in Lake Mývatn Lake Mývatn was created about 2300 years ago by a large fissure eruption pouring out basaltic lava. The lava flowed down Laxárdalur Valley to the lowland plain of Aðaldalur where it entered the Arctic Ocean about 50 km away from Mývatn. The crater row that was formed on top of the eruptive fissure is called Þrengslaborgir (or Lúdentarborgir) and has often been used as a textbook example of this type of volcanic activity. There was a large lake in the area at the time, a precursor of the present-day Mývatn.
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Since both volcanoes generate magma of dacitic origin, the viscous magma builds up since it cannot flow through the eruptive vent. Gradually, the pressure grows, culminating in an explosion that ejects materials such as tephra, which in its simplest form, is ash. Tephrochronology and radiocarbon dating indicate that Glacier Peak eruptions occurred in 1700 AD ± 100 years, 1300 AD ± 300 years, 900 AD ± 50 years, 200 AD ± 50 years, 850 BC, 3150 BC, and in 3550 BC. The Volcanic Explosivity Index (VEI) for three of these was 2 to 4, small compared to the 5 of the 1980 eruption of Mount St. Helens. They were characterized mainly by a central vent eruption, followed by an explosive eruption.
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The geological map of Portugal at the scale of 1:500,000 shows the contact between the Schist-Greywacke Complex of the "Beiras Group" and the Variscan Granitic Complex of the North of Portugal. The "Beiras Group" is formed by a dense series of thin lentils of marine origin, of clay and sandstones, that later suffered low grade regional metamorphism (facies of the green schist) during the initial compressive phases of the Variscan orogeny. The Panasqueira mines are located in the area of the Schist-Greywacke Complex of the Beiras Group, in Central Iberian Zone (ZCI). It is a region where metamorphism sedimentary formations predominates, but where there is also a large number of acidic and basic eruptive manifestations.
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Isolated ridges of lava and hydrothermally altered rock, especially in the area of Sherman Crater, are exposed between glaciers on the upper flanks of the volcano; the lower flanks are steep and heavily vegetated. Volcanic rocks of Mount Baker and Black Buttes rest on a foundation of non-volcanic rocks. Park and Rainbow Glaciers on the northeast flank Deposits recording the last 14,000 years at Mount Baker indicate that Mount Baker has not had highly explosive eruptions like those of other volcanoes in the Cascade Volcanic Arc, such as Mount St. Helens, Glacier Peak, or the Mount Meager massif, nor has it erupted frequently. During this period, four episodes of magmatic eruptive activity have been recently recognized.
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R. Evarts and Fleck originally reported that lava flows at the Barnes Road deposit of the field represented the youngest eruptive products in the Boring area, with a radiometric dating age of 105,000 ± 6,000 years. These eruptions followed a relatively even age distribution over time; geographically, younger vents and associated deposits lie in the northern portion of the field, while older deposits are confined to the south. The products of the Boring Lava Field were erupted discontinuously over an erosion surface. Activity took place during the late Tertiary and early Quaternary, in what is now the Portland area as well as the surrounding area, with a particularly concentrated pocket of activity to the east.
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It is rare that more than 50,000 years pass without an eruption in the region; given the past eruptive history of the field, an eruption is predicted to occur once every 15,000 years on average. About half of the Boring Lava Field eruptions took place in what are today densely populated areas of the Portland–Vancouver metropolitan area. Though the formation of a small cinder cone vent might not extend far beyond its surroundings, depending on location, similar eruptions could lead to deposition of volcanic ash that could lead to serious infrastructural consequences, covering large areas. A larger eruption, like the ones that built Larch Mountain or Mount Sylvania, could extend for years to decades.
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Lava domes and a vent complex formed in the Maunga Puka area, while breccias formed along the vents on the western portion of Rano Aroi crater. This volcano's southern and southeastern flanks are composed of younger flows consisting of basalt, alkali basalt, hawaiite, mugearite, and benmoreite from eruptive fissures starting at 0.24 Ma. The youngest lava flow, Roiho, is dated at 0.11 Ma. The Hanga O Teo embayment is interpreted to be a 200 m high landslide scarp. Rano Raraku and Maunga Toa Toa are isolated tuff cones of about 0.21 Ma. The crater of Rano Raraku contains a freshwater lake. The stratified tuff is composed of sideromelane, slightly altered to palagonite, and somewhat lithified.
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The New England hotspot, also referred to as the Great Meteor hotspot, is a long-lived volcanic hotspot in the Atlantic Ocean. The hotspot's most recent eruptive center is the Great Meteor Seamount, and it probably created a short line of mid to late-Cenozoic age seamounts on the African Plate but appears to be currently inactive.Age Progressive Volcanism in the New England Seamounts and the opening of the Central Atlantic Ocean Retrieved on 2007-10-05 The New England hotspot track is used to estimate the movement of the North American Plate away from the African Plate from early Cretaceous period to the present. The New England hotspot has been overridden by the Mid-Atlantic Ridge.
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Joseph Jean Baptiste Xavier Fournet (May 15, 1801 - January 8, 1869), French geologist and metallurgist, was born at Strasbourg. He was educated at the École des Mines in Paris, and after considerable experience as a mining engineer he was in 1834 appointed professor of geology at Lyon. He was a man of wide knowledge and extensive research, and wrote memoirs on chemical and mineralogical subjects, on eruptive rocks, on the structure of the Jura, the metamorphism of the Western Alps, on the formation of oolitic limestones, on kaolinization and on metalliferous veins. On metallurgical subjects he also was an acknowledged authority; and he published observations on the order of sulphurability of metals (loi de Fournet).
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In a 1974 report by the United States Geological Survey, scientists wrote that "some of the most catastrophic geologic events of the recent past resulted directly or indirectly from volcanism at the site of the Chaos Crags." Pyroclastic flows and avalanches from the formation reached the areas where parts of the Manzanita Lake visitor center facilities now reside. If the Chaos Crags resumed activity, they could erupt pumice, pyroclastic flows, or swift rockfalls, in addition to creating lava domes, though these would not pose major threats to human life should the surrounding area be evacuated promptly. These pyroclastic flows could reach regions directly surrounding the eruptive volcanic vent, and would extend at least into the nearby valley floors.
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As part of this work, the history of Cinder Cone has been reexamined. Most of the features of Cinder Cone have changed little since Harkness first described them in the 1870s, but all of the assumptions on which Finch based his conclusions have now been shown to be incorrect. Through new field and laboratory work and by reinterpreting data from previous studies, USGS scientists have shown that the entire eruptive sequence at Cinder Cone represents a single continuous event. Because the orientation of the Earth's magnetic field in northern California during the 1850s is well known and is different from the remnant magnetizations at Cinder Cone, the lava flows there could not have been erupted in 1850 or 1851.
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The shield-stage lavas that built the enormous main mass of the mountain are tholeiitic basalts, like those of Mauna Kea, created through the mixing of primary magma and subducted oceanic crust. Mauna Loa's summit hosts three overlapping pit craters arranged northeast-southwest, the first and last roughly in diameter and the second an oblong feature; together these three craters make up the summit caldera Mokuʻāweoweo, so named for the Hawaiian ʻāweoweo fish (Priacanthus meeki), purportedly due to the resemblance of its eruptive fires to the coloration of the fish. Mokuʻāweoweo's caldera floor lies between beneath its rim and it is only the latest of several calderas that have formed and reformed over the volcano's life.
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Hayes Volcano is an ice-shrouded, glacially scoured eruptive center of Quaternary age composed of pyroclastic deposits, volcanic breccia, and lava domes. Although the edifice of the volcano is largely covered by glacier ice, parts of small lava domes, dome debris, and pyroclastic deposits project through the ice at altitudes of 2,400 to 2,800 meters above sea level. The volcano is nestled within the Tordrillo Mountains, a rugged, glacier-clad mountain range, between the Alaska Range and Cook Inlet, that is composed primarily of older plutonic igneous rocks. Most of the area is in high relief (greater than 1,500 meters) and supports an extensive complex of glacier ice that covers most of the mountainous terrain.
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The scenario was published in 2003 as an article for Natural Hazards, a Springer journal devoting on all aspects of natural hazards including risk management and the forecasting of catastrophic events. If eruptive activity were to resume, scientists would likely be able to detect increased seismicity as magma makes its way through the crust. The abundance of seismic activity and the sensitivity of the existing Canadian National Seismograph Network in this area would alert the GSC and possibly trigger an expanded monitoring effort. As the magma nears the surface, the volcano would likely swell and the surface fracture, causing greatly increased vigour in the hot springs and the creation of new springs or fumaroles.
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Because of water from the two crater lakes, eruptions at Newberry Volcano may become more explosive and more likely to produce pyroclastic flows. Moreover, if pyroclastic flows mix with snow or water overflowing from the crater lakes, they could spawn lahars, volcanically induced mudslides, landslides, and debris flows that could devastate the Paulina Creek valley and reach the La Pine valley within 30 minutes. Threats from the volcano pose hazards to about 16,400 people who live within and more than 180,000 people living within . In addition to threats from volcanic activity, at least one flood has taken place at Newberry Volcano in the past, though it may not have been a result of eruptive activity.
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Seongsan Ilchulbong The Volcanic crater of Seongsan Ilchulbong Entrance of Seongsan Ilchulbong View from top of Seongsan Ilchulbong Seongsan Ilchulbong, also called ‘Sunrise Peak’, is an archetypal tuff cone formed by hydrovolcanic eruptions upon a shallow seabed about 5 thousand years ago. Situated on the eastern seaboard of Jeju Island and said to resemble a gigantic ancient castle, this tuff cone is 182 meters high, has a preserved bowl-like crater and also displays diverse inner structures resulting from the sea cliff. These features are considered to be of geologic worth, providing information on eruptive and depositional processes of hydromagmatic volcanoes worldwide as well as past volcanic activity of Seongsan Ilchulbong itself.
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Geologists have suggested that "pulses" of magma entering Mauna Loa's deeper magma system may have increased pressure inside Kīlauea and triggered the concurrent eruptions. Kīlauea has a large summit caldera, measuring with walls up to high, breached by lava flows on the southwestern side. It is unknown if the caldera was always there or if it is a relatively recent feature, and it is possible that it has come and gone throughout Kīlauea's eruptive history. What is known is that the summit caldera likely formed over several centuries, with its construction estimated to have begun about 500 years ago, and its present form was finalized by a particularly powerful eruption in 1790.
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Some of the tuyas in the Azas Plateau may have formed through complex eruptive processes. Based on the tuyas of the Tuvan field, it has been determined that ice thicknesses in the area exceeded and that at least three different ice ages occurred in the field. The tuyas in the Azas plateau have been compared to volcanic edifices in the Valles Marineris on Mars. Non-tuya volcanic ice interaction landforms are also found, such as Albine-Bondok, Charash-Dag and Sagan which are subglacial mounds. Glaciation was already in progress under marine isotope stage 5 (127,000 - 71,000 years ago) and by the stage 4 (71,000 - 57,000 years ago) it was continuous over the Azas Plateau.
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Bathymetric diagram of the Axial Seamount, showing the 1998 eruption and segmentation between the CoAxial, Axial, and Vance segments of the ridge The first documented eruption on the Juan de Fuca Ridge took place on the Cleft segment in 1986 and 1987. Hydrothermal megaplumes indicated a large rifting event, releasing hydrothermal fluids as a result of lavas being extruded from a dike. A majority of the eruptions along the ridge are dike injection events, where molten rock is extruded between cracks in the crust's sheeted dike layer. Typically eruptive events can be predicted, as they are preceded by large earthquake swarms in the region. A significant event took place in June 1993, lasting 24 days at the CoAxial segment.
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The most recent recorded volcanic eruption was between 1820 and 1854, but many eyewitnesses reported eruptive activity in 1858, 1870, 1879, 1882, and 1894 as well. Seismic monitors have been placed in Mount Rainier National Park and on the mountain itself to monitor activity. An eruption could be deadly for all living in areas within the immediate vicinity of the volcano and an eruption would also cause trouble from Vancouver, British Columbia, Canada to San Francisco, California because of the massive amounts of ash blasting out of the volcano into the atmosphere. Mount Rainier is located in an area that itself is part of the eastern rim of the Pacific Ring of Fire.
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Espenak earned a bachelor's degree in physics from Wagner College, Staten Island, where he worked in the planetarium. His master's degree is from the University of Toledo, based on studies he did at Kitt Peak Observatory of eruptive and flare stars among red dwarfs. Espenak with his solar telescope He was employed at Goddard Space Flight Center, where he used infrared spectrometers to measure the atmosphere of planets in the Solar System. He provided NASA's eclipse bulletins since 1978. He is the author of several canonical works on eclipse predictions, such as the Fifty Year Canon of Solar Eclipses: 1986–2035 and Fifty Year Canon of Lunar Eclipses: 1986-2035, both of which are standard references on eclipses.
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The Wells Gray-Clearwater volcanic field is one of the 10 volcanic areas in Canada associated with recent seismic activity; the others are Castle Rock, Mount Edziza, Mount Cayley, Hoodoo Mountain, The Volcano, Crow Lagoon, Mount Meager massif, Mount Garibaldi and Nazko Cone. Seismic data suggests that these volcanoes still contain living magma plumbing systems, indicating possible future eruptive activity. Although the available data does not allow a clear conclusion, these observations are further indications that some of Canada's volcanoes are potentially active, and that their associated hazards may be significant. Beneath areas of monogenetic cinder cone activity, such as the Wells Gray-Clearwater volcanic field, the seismicity appears to be more dispersed.
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Structure of the Cascadia subduction zone As the last of the Kula Plate decayed and the Farallon Plate advanced back into this area from the south, it once again started to subduct under the continental margin of Western Canada 37 million years ago, supporting a chain of volcanoes called the Cascade Volcanic Arc. At least four volcanic formations along the British Columbia Coast are associated with Cascadia subduction zone volcanism. The oldest is the eroded 18-million- year-old Pemberton Volcanic Belt which extends west-northwest from south- central British Columbia to the Queen Charlotte Islands in the northeast where it lies west of mainland British Columbia. In the south it is defined by a group of epizonal intrusions and a few erosional remnants of eruptive rock.
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In medical school, Dr. Fisher had studied with Dr. James Jackson, Harvard's first professor of clinical medicine and one of the "fathers" of Massachusetts General Hospital. Dr. Jackson had touched on the difficulties of distinguishing smallpox from other eruptive diseases and the need for a series of colored pictures which would illustrate the progress of the disease. Dr. Fisher undertook such a project while in Paris and wrote Description of the Distinct, Confluent, and Inoculated Small Pox, Varioloid Disease, Cow Pox, and Chicken Pox (1829) which included thirteen colored plates. The paintings from which the plates were made were executed under Dr. Fisher's direction by a French artist working at the bedside of the patients during 1825 and 1826 when smallpox was an epidemic in Paris.
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Silverthrone Caldera is one of the eleven Canadian volcanoes associated with recent seismic activity: the others are Castle Rock, Mount Edziza, Mount Cayley massif, Hoodoo Mountain, The Volcano, Crow Lagoon, Mount Garibaldi, Mount Meager massif, Wells Gray-Clearwater Volcanic Field and Nazko Cone. Seismic data suggests that these volcanoes still contain live magma plumbing systems, indicating possible future eruptive activity. Although the available data does not allow a clear conclusion, these observations are further indications that some of Canada's volcanoes are potentially active, and that their associated hazards may be significant. The seismic activity correlates both with some of Canada's most youthful volcanoes, and with long-lived volcanic centers with a history of significant explosive behavior, such as the Silverthrone Caldera.
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A first eruptive episode was phreatomagmatic and generated a low eruption column which in turn gave rise to pyroclastic flows and pyroclastic surges, which were heavily influenced by the topography as they propagated and then came to rest, giving rise to several geological units which are each thick. These units include a lithic unit formed by pre-existent country rock which overlies other units and is sometimes embedded into them as lens-like forms, and a pumice fall deposit that has undergone hydrothermal alteration and fluvial erosion in part. At least three lapilli tuff units are present, the thickest of which has a massive structure and reaches a thickness of . An obsidian containing facies is found inside of one vent of the volcano.
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The Alaska Volcano Observatory (AVO) is a joint program of the United States Geological Survey, the Geophysical Institute of the University of Alaska Fairbanks, and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS).dggs.alaska.gov AVO was formed in 1988, and uses federal, state, and university resources to monitor and study Alaska's volcanology, hazardous volcanoes, to predict and record eruptive activity, and to mitigate volcanic hazards to life and property. The Observatory website allows users to monitor active volcanoes, with seismographs and webcameras that update regularly. AVO now monitors more than 20 volcanoes in Cook Inlet, which is close to Alaskan population centers, and the Aleutian Arc due to the hazard that plumes of ash pose to aviation.
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Indian Heaven consists of several, overlapping shield volcanoes that run along a line from Sawtooth Mountain at the north to Red Mountain to the south, as well as cinder cones, lava flows, and spatter cones (low, steep- sided hills or mounds that consist of welded lava fragments). With a total magma output of , the field has about 50 mafic eruptive edifices (rich in magnesium and iron), whose activity lasted from the Pleistocene to the early Holocene. Roughly half of these vents mark a mountainous highland, in length, which runs parallel to the north–south trend of the Cascade Arc in southern Washington state. Most of the volcanoes that comprise the Indian Heaven field are monogenetic, only erupting once before becoming extinct.
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Deformation was occurring at rates up to a centimetre a day since 4 March at various GPS sites installed within from the eruptive site. A fissure opened up about in length running in a north-east to south- west direction, with 10 to 12 erupting lava craters ejecting lava at a temperature around up to into the air. The lava was alkali olivine basalt and was relatively viscous, causing the motion of the lava stream to the west and east of the fissure to be slow. The molten lava flowed more than to the north- east of the fissure and into Hrunagil canyon, forming a lava fall more than long and slowly approaching Þórsmörk, but had not reached the flood plains of Krossá.
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Proceeding to Edinburgh to study medicine at the university, he came under the influence of Robert Jameson, whose teachings in geology and mineralogy inspired his future career. Boué was thus led to make geological expeditions to various parts of Scotland and the Hebrides, and after taking his degree of M.D. in 1817 he settled for some years in Paris. In 1820 he issued his Essai géologique sur l'Écosse, in which the eruptive rocks in particular were carefully described. He travelled much in Germany, Austria and southern Europe, studying various geological formations, and becoming one of the pioneers in geological research; he was one of the founders of the Société Géologique de France in 1830, and was its president in 1835.
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Therefore, CO2 emissions during volcanic eruptions are less than 10% of CO2 emissions released during non-eruptive volcanic activity. The 15 June 1991 eruption of Mount Pinatubo (VEI 6) in the Philippines released a total of 18 ± 4 Tg of SO2. Such large VEI 6 eruptions are rare and only occur once every 50 – 100 years. The 2010 eruptions of Eyjafjallajökull (VEI 4) in Iceland emitted a total of 5.1 Tg CO2. VEI 4 eruptions occur about once per year. For comparison, the human activity of burning fossil fuels and the production of cement released 36,300 Tg CO2 into the atmosphere in 2015. Therefore, the amount of CO2 emitted due to human activity is 600 times the amount of CO2 presently released by volcanoes.
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The flow subsequently stopped short of Zafferana. The program has significantly increased what is known about the Decade Volcanoes, some of which were very poorly studied before being designated. The eruptive history of Galeras volcano is now much better established than previously, and at Taal Volcano the importance of water in driving its explosive eruptions has come to light. Measures which have been taken to mitigate disasters which might be caused by future eruptions include a new law in the vicinity of Mount Rainier, requiring assessment of geological hazards before any new developments; limitations on high density housing developments in the Taal Caldera; and the development of an evacuation plan for parts of Naples which might be affected in the event of an eruption at Vesuvius.
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Under Smith's leadership, their regiment and brigade were now part of the larger Army of the Potomac, and would help to defend the nation's capital through late January when the men of the 47th Pennsylvania would be shipped south. The weather during this time was reported in letters home from the men to be cold and damp; several men from the regiment fell ill. Eleven days after the death of drummer boy John Boulton Young, Sergeant Frank M. Holt also succumbed to Variola at the Kalorama eruptive fever hospital (on 28 October 1861). Sometime that same month, according to Schmidt, Private Reuben Wetzel from G Company, was seriously injured while the regiment was engaged in relocating to Camp Griffin in Virginia.
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The volcano's glaciers have extensively altered its profile, cutting, deep and creating steep cliffs and cirques. A ridge extends south from the main body of the mountain, with North Twin and South Twin peaks along its length. There is no summit crater, only a zone of fumaroles just south of the summit at the top of large collapse zone at the head of Red Glacier, which exposes a cross section of the mountain. Holocene eruptive activity from Iliamna is little known, but radiocarbon dating seems to indicate at least a few eruptions, all before the European settlement of Alaska. Prehistoric eruptions have been dated to 5050 and 2050 BCE (VEI 4), 450 BCE, 1650, 1867 (VEI 2) and 1876 (VEI 3).
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More than 100 eruptions have occurred in the past 20 million years with a broad range of eruptive styles. These volcanic processes have created a range of different volcanic landforms, including stratovolcanoes, shield volcanoes, lava domes and cinder cones, along with a few isolated examples of rarer volcanic forms such as tuyas. Large persistent volcanoes of the Northern Cordilleran Volcanic Province can remain dormant for hundreds or thousands of years between eruptions and therefore the greatest risk caused by volcanic activity is not always readily apparent. Volcanics older than 14 million years are mainly found in the northern portion of the volcanic province while volcanics ranging from nine to four million years old exist only in the middle of the volcanic province.
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Only at this point does the organ let out a real roar, a moment savoured by Latry." Jim Farber of the San Francisco Classical Voice declared it a "superb example" of Saariaho's music, opining, "At times the organ blends into the orchestral fabric as a rumbling, pulsing, growling presence. Then like a magma pool no longer under restraint, it bursts forth in eruptive crescendos of full-voiced magnitude causing tectonic shifts in the orchestral landscape." Conversely, Andrew Clements of The Guardian called the work "a curious piece" and remarked, "The three movements flit in and out of focus, and the solo writing seems to reference a century's worth of the organ repertoire from Franck, through Reger, to Messiaen and Langlais.
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The recognised summit is at 388m to the South of the hill, but the highest point, named Cerrig-y-Myllt on only the most detailed UK Ordnance Survey mapping, is at 463m above the two small lakes to the North of the hill. The craggy nature of the hill is due to the presence of lavas and tuffs (volcanic ash deposits) dating from the Ordovician period when Snowdonia was characterised by numerous volcanic eruptions; Yr Arddu is a particularly good location to see the record of Ordovician volcanism. The Yr Arddu Tuffs may be the earliest eruptive phase of the Lower Rhyolitic Tuff Formation. The whole hill is a site of special scientific interest designated by the Countryside Council for Wales.
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This eruptive period postdates the formation of the Garibaldi Belt and evidence for more recent volcanism in the Alert Bay Belt has not been found, indicating that volcanism in the Alert Bay Belt is likely extinct. Bedrock under the Garibaldi chain consists of granitic and dioritic rocks of the Coast Plutonic Complex, which makes up much of the Coast Mountains. This is a large batholith complex that was formed when the Farallon and Kula plates were subducting along the western margin of the North American Plate during the Jurassic and Tertiary periods. It lies on island arc remnants, oceanic plateaus and clustered continental margins that were added along the western margin of North America between the Triassic and Cretaceous periods.
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Postglacial, mafic eruptions are more common in the Sisters Reach — which includes Belknap — than anywhere in the Cascade volcanic arc. A lava flow lies next to South Cinder Peak, the Nash Crater–Lost Lake cone cluster, Sand Mountain Volcanic Field, Inaccessible Cone chain, Blue Lake Crater, and a number of monogenetic scoria cones and chains. The McKenzie and Santiam Pass area saw more than a dozen distinct mafic eruptions between 4,500 and 1,100 years ago according to radiocarbon dating, which corresponded to a pulse of mafic eruptions in the late Holocene epoch. Other nearby mafic eruptive units occur at Sims Butte, Cayuse Crater, LeConte Crater, Mount Bachelor, the Egan Cone cluster, and the Katsuk-Talapus chain, which likely were all emplaced between 18,00 and 8,000 years ago.
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Three Fingered Jack as seen from alt=Three Fingered Jack can be seen in the top left of the image, with a heavily forested area and a lake beneath Three Fingered Jack is a shield volcano, and it is part of the group of volcanoes known as Oregon's Matterhorns, whose tall, pinnacle spires resemble the Matterhorn in Switzerland. The volcano, along with Mount Thielsen, Mount Bailey, Diamond Peak, and Mount Washington, had a shorter lifespan than larger volcanoes in the Cascade Range, ceasing eruptive activity more than 100,000 years ago. Three Fingered Jack marks the northernmost point for this group. South of Mount Jefferson, the High Cascades of Oregon consist of a broad ridge produced by shield volcano activity and eruptions from cinder cones.
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Nearby volcanic vents include the Sisi Butte, South Pinhead, and West Pinhead shield volcanoes and the Fort Butte, North Pinhead, and Potato Butte cinder cones. Cinder cones in the area have gray-red cinders that have been oxidized, scoria, agglomerate, and small lava flows consisting of porphyritic basaltic andesite and black and yellow-brown to dark yellow-orange, palagonite basaltic andesite. The black and orange color of some of the eruptive material from these cones suggests that there was interaction of the lava with wet ground or snow, causing rapid chilling of the ejecta that prevented oxidation from taking place. At Double Peaks and an unnamed hill southwest of View Lake, there are gray-pink to light brown-gray hornblende dacite lava domes.
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The volcanic cones at Olallie Butte and Mount Jefferson were erupted over deposits from the Minto lava group, which have been deeply eroded to create non-conforming surfaces. As a result, Olallie Butte has a relatively steeper slope, but there are lithologic similarities between the Olallie lavas and Minto lavas. Whereas Minto volcanoes follow a narrow, nearly linear arrangement south of Olallie Butte, north of Olallie the local volcanoes exhibit a scattered distribution across the plateau of the High Cascades. There are also transitional volcanoes not easily classified into either the Minto or Olallie group; their acidic composition suggests that they differentiated during the Minto eruptive phase, but progressive differentiation has been observed in the region, making definite conclusions about their categorization difficult.
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In the 1970s, a mapping project was initiated to gain more information about the complex geology of Hawaii's seafloor. The hotspot has since been tomographically imaged, showing it to be wide and up to deep, and olivine and garnet-based studies have shown its magma chamber is approximately . In its at least 85 million years of activity the hotspot has produced an estimated of rock. The chain's rate of drift has slowly increased over time, causing the amount of time each individual volcano is active to decrease, from 18 million years for the 76-million-year-old Detroit Seamount, to just under 900,000 for the one-million-year-old Kohala; on the other hand, eruptive volume has increased from per year to about .
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It has a mountain ridge that extends along the centre of the island, reaching at its highest point (Pico Ruivo), while much lower (below 200 metres) along its eastern extent. The primitive volcanic foci responsible for the central mountainous area, consisted of the peaks: Ruivo (1,862 m), Torres (1,851 m), Arieiro (1,818 m), Cidrão (1,802 m), Cedro (1,759 m), Casado (1,725 m), Grande (1,657 m), Ferreiro (1,582 m). At the end of this eruptive phase, an island circled by reefs was formed, its marine vestiges are evident in a calcareous layer in the area of Lameiros, in São Vicente (which was later explored for calcium oxide production). Sea cliffs, such as Cabo Girão, valleys and ravines extend from this central spine, making the interior generally inaccessible.
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Volcanogenic massive sulfide deposits are forming today on the seafloor around undersea volcanoes along many mid ocean ridges, and within back-arc basins and forearc rifts. Mineral exploration companies are exploring for seafloor massive sulfide deposits; however, most exploration is concentrated in the search for land-based equivalents of these deposits. The close association with volcanic rocks and eruptive centers sets VMS deposits apart from similar ore deposit types which share similar source, transport and trap processes. Volcanogenic massive sulfide deposits are distinctive in that ore deposits are formed in close temporal association with submarine volcanism and are formed by hydrothermal circulation and exhalation of sulfides which are independent of sedimentary processes, which sets VMS deposits apart from sedimentary exhalative (SEDEX) deposits.
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Radiocarbon dating has established that Mount Tambora had erupted three times during the current Holocene epoch before the 1815 eruption, but the magnitudes of these eruptions are unknown. Their estimated dates are 3910 BC ± 200 years, 3050 BC and 740 AD ± 150 years. An earlier caldera was filled with lava flows starting from 43,000 years BP; two pyroclastic eruptions occurred later and formed the Black Sands and Brown Tuff formations, the last of which was emplaced between about 3890 BC and 800 AD. In 1812, Mount Tambora became highly active, with its maximum eruptive intensity occurring in April 1815. The magnitude was 7 on the Volcanic Explosivity Index (VEI) scale, with a total tephra ejecta volume of up to 1.8 × 1011 cubic metres.
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The Global Volcanism Program reports that the field includes somewhere between 32 and 50 shield volcanoes and cinder cones, with many vents concentrated northwest of the town of Boring. Considered an outlier of the Cascade Range, the Boring Lava Field lies about to the west of the major Cascade crest. It marks one of five volcanic fields along the Quaternary Cascade arc, along with Indian Heaven, Tumalo in Oregon, the Mount Bachelor chain, and Caribou in California. Like the Cascade Range, the Boring field was also generated by the subduction of the oceanic Juan de Fuca tectonic plate under the North American tectonic plate, but it has a different tectonic position, with its eruptive activity more likely related to tectonic rifting throughout the region.
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Under Parkes's editorship Tripe contributed valuable memoirs on 'Scarlatinal Dropsy and the Mortality from the Eruptive Fevers'; and, under Dr. Sieveking, he contributed a paper on 'The Relative Mortality of Males and Females under Five Years of Age', and one on 'Poisoning by Sausages'. Sir Edward Sieveking says of him: " I think all his articles would deserve reading at the present day, as they show much research and observation." But, as we have already intimated, his great merit consisted in throwing the light of the allied science of meteorologymore especially on the problems of hygiene. He early in life joined the Royal Meteorological Society, and the part he played in it was no less honourable to himself than signal in its services to the Society.
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He presented his conclusions at a meeting of the California Academy of Sciences, and was contacted by Academy member Henry Chapman, who informed him of the gold prospector story. A number of other people reached out to Harkness about seeing volcanic activity in Lassen in about 1851, such as O. M. Wozencraft, which led Harkness to think that Cinder Cone had erupted recently. Though there were multiple reports of eruptive activity near Lassen in Northern California newspapers during the 1850s, the details remain inconsistent. The first such report, which was published in the August 21, 1850, edition of the Daily Pacific News (a San Francisco newspaper), cited an unnamed observer who claimed to have seen "burning lava still running down the sides" at Cinder Cone.
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The Pāhala ashes themselves were produced over a long period of time circa 13 to 30 thousand years ago, although heavy vitrification and interactions with post and pre- creation flows has hindered exact dating. Their age roughly corresponding with the glaciation of Mauna Loa during the last ice age, raising the distinct possibility that it is the product of phreatomagmatic interaction between the long-gone glaciers and Mauna Loa's eruptive activities. Studies have shown that a cycle occurs in which volcanic activity at the summit is dominant for several hundred years, after which activity shifts to the rift zones for several more centuries, and then back to the summit again. Two cycles have been clearly identified, each lasting 1,500–2,000 years.
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Some basalt lava flows occur on the edges of Mount Washington at the Cache Creek and Dry Creek canyons or as outcrops that form benches (long, relatively narrow strips of relatively level or gently inclined land bounded by distinctly steeper slopes above and below) about away from Washington from Patjens Lake to the McKenzie River. Washington is part of the informal group of volcanoes known as Oregon's Matterhorns, which includes Mount Thielsen, Three Fingered Jack, Mount Bailey, and Diamond Peak. The name originates from the spire-like appearance of the volcanoes' summits, which resembles the pinnacle of the Matterhorn in Switzerland. They all ceased eruptive activity at least 100,000 to 250,000 years ago, leading to their extensive dissection by glaciers over time.
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Its physiographic province is deep, but it is unknown whether it is a shallow listric fault or if it penetrates to the very base of the volcano. In connection with the 2018 lower Puna eruption the Hawaiian Volcano Observatory published some facts leading to the conclusion, that a catastrophic collapse would be incredibly remote. A number of cinder cones, satellite shields, lava tubes, and other eruptive structures also dot the volcano, evidence of its recent activity. Kīlauea has some interactions with Mauna Loa, its larger neighbor and only other recently active volcano on the island; interspersed lava flows and ash deposits belonging to its neighbor have been found on its flanks, and some of Mauna Loa's flows are, in turn, blanketed in Kīlauea tephra.
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The Mauna Ulu eruption of 1969 generated a -high lava fountain After the Halemaumau event, Kīlauea remained relatively quiet, and for a time, completely silent, with all activity confined to the summit. The volcano came alive again in 1952, with an enormous lava fountain high at Halemaʻumaʻu. Multiple continuous lava fountains between persisted, and the eruption lasted 136 days. Eruptions occurred soon after in 1954, 1955, and 1959, capped by a large event in 1960, when fissure-based phreatic eruption and earthquake activity gave way to a massive ʻaʻā flow that overran multiple evacuated communities and resorts; the resulting summit deflation eventually caused the ever-active Halemaumau to collapse even further. From 1960 on, eruptive events occurred frequently until August 2018.
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Hoodoo Mountain is one of the eleven Canadian volcanoes associated with recent seismic activity: the others are Mount Garibaldi, Castle Rock, Mount Cayley massif, The Volcano, Crow Lagoon, Silverthrone Caldera, the Mount Meager massif, the Mount Edziza volcanic complex, Wells Gray-Clearwater volcanic field and Nazko Cone. Seismic data suggests that these volcanoes still contain living magma chambers, indicating possible future eruptive activity. Although the available data does not produce a clear conclusion, these observations are further indications that some of Canada's volcanoes are potentially active, and that their associated hazards may be significant. The seismic activity correlates both with some of Canada's most youthful volcanoes, and with long-lived volcanoes with a history of significant explosive activity, such as Hoodoo Mountain.
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The Tamu Massif was formed about 145 million years ago during the Late Jurassic to Early Cretaceous period over a relatively short period of time (a few million years) and then became extinct. Tamu Massif was formed during one, geologically brief eruptive period, which scientists had previously thought was impossible on Earth. If confirmed, the suggestion that it could be a single volcano would make the Tamu Massif the largest known volcano on Earth, dwarfing the current record-holder, Pūhāhonu, in the Hawaiian Islands. The main part of Tamu's rounded dome extends over an area of , totaling more than , many times larger than Mauna Loa, which has an area of , and about half the area of the Martian volcano Olympus Mons.
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Considered an outlier of the Cascade Range, the Boring Lava Field lies about to the west of the major Cascade crest. It marks one of five volcanic fields along the Quaternary Cascade arc, along with Indian Heaven, Tumalo in Oregon, the Mount Bachelor chain, and Caribou in California. Like the Cascade Range, the Boring field was also generated by the subduction of the oceanic Juan de Fuca tectonic plate under the North American tectonic plate, but it has a different tectonic position, with its eruptive activity more likely related to tectonic rifting throughout the region. The Boring Lava Field has erupted material derived from hot mantle magma, and the subducting Juan de Fuca plate may be as shallow as in depth at their location.
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This volcanic activity built an extensive lava plateau and large igneous province with an area of representing a volume of lavas of at least . With an area of and a volume of at least , it is larger than the Columbia River Basalt Group in the United States and comparable in size to the Deccan Traps in west-central India, making it one of the largest flood basalt events ever to appear on the North American continent, as well as on Earth. This massive eruptive event was associated with the Mackenzie magmatic event, that included the coeval, layered, mafic- ultramafic Muskox intrusion and the enormous Mackenzie dike swarm that diverges from the Coppermine River flood basalts. The maximum thickness of the flood basalts are and consist of 150 lava flows, each thick.
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The Thlewyco sequence represents the main construction phase of the volcano and forms an outward dipping, annular succession around the Innerring sequence, with an aggregate thickness of -. Its stratigraphy changes dramatically around the crater, varying from five cycles of andesitic and rhylotic lava, followed by succession of volcanistic debris on the north side, to 30 subaerial andesitic flows and rare pyroclastic and epivolcaniclastic units on the eastern side, to interlayered dacitic and andesitic lava and tuff overlain by a thick succession of voluminous, nonwelded, ash-flow tuff and volcaniclastic rocks on the south side. Volcanism in this sequence ended with the eruption of large rhyolite and dacite dome-flow complexes (U-Pb zircon dated at 2.692 Ga). The Innerring and Thlewycho sequences represent a complex history of explosive eruptions from numerous eruptive centers.
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NGC 6302 has a complex structure, which may be approximated as bipolar with two primary lobes, though there is evidence for a second pair of lobes that may have belonged to a previous phase of mass loss. A dark lane runs through the waist of the nebula obscuring the central star at all wavelengths. The nebula contains a prominent northwest lobe which extends up to 3.0′ away from the central star and is estimated to have formed from an eruptive event around 1,900 years ago. It has a circular part whose walls are expanding such that each part has a speed proportional to its distance from the central star. At an angular distance of 1.71′ from the central star, the flow velocity of this lobe is measured to be 263 km/s.
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Quilotoa () is a water-filled crater lake and the most western volcano in the Ecuadorian Andes. The -wide caldera was formed by the collapse of this dacite volcano following a catastrophic VEI-6 eruption about 600 years ago, which produced pyroclastic flows and lahars that reached the Pacific Ocean, and spread an airborne deposit of volcanic ash throughout the northern Andes. This last eruption followed a dormancy period of 14,000 years and is known as the 1280 Plinian eruption.Patricia A. Mothes, Minard L. Hall (2008) "The plinian fallout associated with Quilotoa's 800 yr BP eruption, Ecuadorian Andes", Journal of Volcanology and Geothermal Research, Volume 176, Issue 1, 10 September 2008, Pages 56-69 The fourth (of seven) eruptive phase was phreatomagmatic, indicating that a Crater lake was already present at that time.
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In this interpretation, the streamlined island-like forms are interpreted to show a highstand (where the lava level reached a maximum height) prior to the drainage and pooling of molten material downstream into Cerberus Palus. Nearly the entire surface of the Athabasca Valles floor has been interpreted by some authors to morphologically parallel the Roza Member of the Wanapum Basalt, a unit within the Columbia River Basalt Group in the American Northwest; those researchers propose that the entire floor unit was deposited in a single eruptive event, with lavas in the area depositing turbulently as part of a flooding event. Lava flows downstream of the Athabasca Valles in Cerberus Palus in this HiRISE image. Putative lava coils are observed in this image and are on a scale of meters in diameter.
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When the first geological reconnaissance of the Three Sisters region was published in 1925, its author, Edwin T. Hodge, suggested that the Three Sisters and five smaller mountains in the present-day wilderness area were the remains of an enormous collapsed volcano that had been active during the Miocene or early Pliocene epochs. Naming this ancient volcano Mount Multnomah, Hodge theorized that it had collapsed to form a caldera just as Mount Mazama collapsed to form Crater Lake. In the 1940s, Howel Williams completed an analysis of the Three Sisters vicinity and concluded that Multnomah had never existed, instead demonstrating that each volcano in the area possessed its own individual eruptive history. Williams' 1944 paper defined the basic outline of the Three Sisters vicinity, though he lacked access to chemical techniques and radiometric dating.
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Although taking its name from the Cascade Range, this term is a geologic grouping rather than a geographic one, and the Cascade Volcanoes extend north into the Coast Mountains, past the Fraser River which is the northward limit of the Cascade Range proper. Some of the major cities along the length of the arc include Portland, Seattle, and Vancouver, and the population in the region exceeds 10 million. All could be potentially affected by volcanic activity and great subduction-zone earthquakes along the arc. Because the population of the Pacific Northwest is rapidly increasing, the Cascade volcanoes are some of the most dangerous, due to their eruptive history and potential for future eruptions, and because they are underlain by weak, hydrothermally altered volcanic rocks that are susceptible to failure.
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Immediately after the explosion, the vari-colored lakes had disappeared and in their place was one large lake, about ten feet below the level of the lake surrounding the island. The crater lake gradually rose until it is on a level with the water in Taal Lake. Popular opinions after the creation of the lake held that the presence of the water in the crater has a tendency to cool off the material below and thus lessen the chances of an explosion or make the volcano extinct, but the preponderance of expert opinion was otherwise.(The subsequent eruption in 1965 and succeeding activities came from a new eruptive center, Mount Tabaro.) Ten years after the eruption, no changes in the general outline of the island could be discerned at a distance.
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Because they are rapidly cooled, they represent the liquid composition of the komatiites, and thus record an anhydrous MgO content of up to 32% MgO. Some of the highest magnesian komatiites with clear textural preservation are those of the Barberton belt in South Africa, where liquids with up to 34% MgO can be inferred using bulk rock and olivine compositions. The mineralogy of a komatiite varies systematically through the typical stratigraphic section of a komatiite flow and reflects magmatic processes which komatiites are susceptible to during their eruption and cooling. The typical mineralogical variation is from a flow base composed of olivine cumulate, to a spinifex textured zone composed of bladed olivine and ideally a pyroxene spinifex zone and olivine-rich chill zone on the upper eruptive rind of the flow unit.
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Topographic map of the ice cap on Hoodoo Mountain's flat-top summit At least five volcanoes have had seismic activity since 1985, including the Mount Edziza volcanic complex (eight events), Castle Rock (two events), Hoodoo Mountain (eight events), Crow Lagoon (four events) and The Volcano (five events). Seismic data suggests that these volcanoes still contain living magma chambers, indicating possible future eruptive activity. Although the available data does not allow a clear conclusion, these observations are further indications that some Northern Cordilleran volcanoes are potentially active and that their associated hazards may be significant. The seismic activity correlates both with some of Canada's most youthful volcanoes and with long- lived volcanoes with a history of significant explosive activity, such as Hoodoo Mountain and the Mount Edziza volcanic complex.
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There have been at least five mass extinctions in the history of life on earth, and four in the last 350 million years in which many species have disappeared in a relatively short period of geological time. A massive eruptive event, that released large quantities of tephra particles into the atmosphere, is considered to be one likely cause of the "Permian–Triassic extinction event" about 250 million years ago, which is estimated to have killed 90% of species then existing. There is also evidence to suggest that this event was preceded by another mass extinction, known as Olson's Extinction. The Cretaceous–Paleogene extinction event (K–Pg) occurred 66 million years ago, at the end of the Cretaceous period, and is best known for having wiped out non-avian dinosaurs, among many other species.
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This volcanic activity built an extensive lava plateau and large igneous province with an area of representing a volume of lavas of at least . With an area of and a volume of , it is larger than the Columbia River Basalt Group in the United States and comparable in size to the Deccan Traps in west-central India, making it one of the largest flood basalt events ever to appear on the North American continent, as well as on Earth. This massive eruptive event was associated with the Mackenzie magmatic event, that included the coeval, layered, mafic-ultramafic Muskox intrusion and the enormous Mackenzie dike swarm that diverges from the Coppermine River Group flood basalts. The maximum thickness of the flood basalts are and consist of 150 lava flows, each to thick.
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As part of Operation St. Elias, Jack Souther studied the stratigraphy, structure and evolution of the Wrangell lavas of southwest Yukon in the mid 1970s. He was surprised by the difference in volcanic style between the Wrangell lavas where an enormous volume of andesite lava had issued without any apparent breaks and was accompanied by profound tectonic uplift and compressive folding, in contrast to the episodic eruption of alkaline basalt and highly fractionated silicic peralkaline rocks at Edziza. The differences in eruptive style and chemistry of the Wrangell lavas led Souther to speculate they were related to a calc-alkaline volcanic arc that formed along a converging plate boundary. In 1977, a book published under the title Volcanic Regimes in Canada included a chapter on Cordilleran tectonics by Jack Souther.
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The Table and Mount Garibaldi as seen from The Black Tusk Meadows Mount Garibaldi is one of the eleven Canadian volcanoes most strongly associated with recent seismic activity; the others are Castle Rock, Mount Edziza, Mount Cayley massif, Hoodoo Mountain, The Volcano, Crow Lagoon, Silverthrone Caldera, Mount Meager massif, Wells Gray-Clearwater Volcanic Field and Nazko Cone. The mountain is informally described as "dormant" ("asleep") because the mountain has not erupted in historic times, nor does it display fumarolic activity like nearby Mount Baker. However, seismic data suggests that these volcanoes still contain living magma plumbing systems, indicating possible future eruptive activity. Although the available data does not allow a clear conclusion, these observations are further indications that some of Canada's volcanoes are potentially active, and that their associated hazards may be significant.
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There is some evidence to link the Deccan Traps eruption to the contemporaneous asteroid impact that created the nearly antipodal Chicxulub crater in the Mexican state of Yucatán. Although the Deccan Traps began erupting well before the impact, argon-argon dating suggests that the impact may have caused an increase in permeability that allowed magma to reach the surface and produced the most voluminous flows, accounting for around 70% of the volume. The combination of the asteroid impact and the resulting increase in eruptive volume may have been responsible for the mass extinctions that occurred at the time that separates the Cretaceous and Paleogene periods, known as the K–Pg boundary. A more recent discovery appears to demonstrate the scope of the destruction from the impact alone, however.
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The Boring Lava Field represents the youngest episode of volcanism within the Cascade forearc, and while there is no evidence that they were associated with a slab window (a gap that forms in a subducted oceanic plate when a mid-ocean ridge meets with a subduction zone and plate divergence at the ridge and convergence at the subduction zone continue, causing the ridge to be subducted), they likely interacted with the regional mantle wedge. The Boring Lava Field shows a similar composition to the High Cascades that run through Oregon and southern Washington state, with Pliocene to Pleistocene basalt lava flows and breccias. It was active during the late Tertiary into the early Quaternary. Within the field, lava shows a diverse composition overall, varying from low-K, tholeiitic to high-K, calc-alkaline eruptive products.
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Lava flows coming out of Mount Edziza The Mount Edziza volcanic complex is one of the eleven Canadian volcanoes associated with recent seismic activity: the others are Castle Rock, Mount Garibaldi, Mount Cayley, Hoodoo Mountain, The Volcano, Crow Lagoon, Silverthrone Caldera, Mount Meager massif, Wells Gray-Clearwater volcanic field and Nazko Cone. Seismic data suggests that these volcanoes still contain live magma plumbing systems, indicating possible future eruptive activity. Although the available data does not allow a clear conclusion, these observations are further indications that some of Canada's volcanoes are potentially active, and that their associated hazards may be significant. The seismic activity correlates both with some of Canada's most youthful volcanoes, and with long-lived volcanic centres with a history of significant explosive behavior, such as the Mount Edziza volcanic complex.
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For most volcanic centers in the Southern Cascades, one volcano becomes active and normally becomes extinct as another begins to erupt, but at the Lassen locus, the Maidu and Dittmar volcanic centers overlapped during the late Pliocene to the early Pleistocene. Volcanism within the Lassen vicinity follows a trend of intermittent, episodic eruptions punctuating long periods of dormancy, a pattern which persisted through the late Pleistocene and Holocene. During the past 825,000 years, the area has produced hundreds of explosive eruptions over an area of , and the past 50,000 years have seen seven major silicic eruptive episodes that produced dacitic lava domes, tephra, and pyroclastic flows, along with five periods of basaltic and andesitic lava flows. Local activity began 600,000 years ago with the formation of Brokeoff Volcano (alternatively known as Mount Tehama).
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These include a number of caldera-forming eruptions, producing ash flow deposits including the Tepee Draw tuff and Black Lapilli tuff, and rising or more into the stratosphere. The last of these eruptions covered tens of thousands of square miles with ash, extending to the San Francisco Bay Area in California nearly to the southwest. Here, it reaches a thickness of one centimeter. Additionally, Newberry has produced multiple, voluminous explosive eruptions, with certain studies estimating up to 60 eruptive events of rhyolite and dacite tephra that reach Idaho, Utah, and northern California. These include the eruption that produced the Paulina Creek tephra between 55,000 and 50,000 years ago, and the eruption from 20,000 years ago responsible for the Wono tephra, which extends into western Nevada and east-central California.
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Rainbow and volcanic ash with sulfur dioxide emissions from Halemaʻumaʻu Geologists have dated and documented dozens of major eruptions over the volcano's long history, bridging the long gap between Kīlauea's oldest known rock and only extremely recent written records and historical observation. Historical lava flows from the volcano are generally recovered by scientists in one of three ways. The oldest flows, dating back 275,000 to 225,000 years, have been recovered from Kīlauea's submerged southern slope by ship-towed remotely operated vehicles. These lavas exhibit forms characteristic of early, submerged preshield-stage eruptive episodes, from when the volcano was still a rising seamount that had not yet breached the ocean surface, and their surface exposure is unusual, as in most other volcanoes such lavas would have since been buried by more recent flows.
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Today, tourism is driven by the island's exotic tropical locations, and Kīlauea, being one of the few volcanoes in the world in a more or less constant state of moderate eruption, was a major part of the island's tourist draw. According to the National Park Service, Kīlauea is visited by roughly 2.6 million people annually, most of whom proceeded to visit the volcano from the Kilauea Visitor Center near the park entrance. The Thomas A. Jaggar Museum was also a popular tourist stop. Located at the edge of Kīlauea Caldera, the museum's observation deck offered the best sheltered view on the volcano of the activity at Halemaʻumaʻu; however, the museum closed indefinitely after the building housing it sustained structural damage from earthquakes associated with the 2018 eruptive episodes.
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Only a few outcrops of Mount Moulton have been dated and these yield ages of 5.3 million years, with further age estimates of 4.9 – 4.7 million years ago and 5.9 million years ago; there is no evidence of eruptive or thermal activity unlike at its neighbour Mount Berlin. Earthquakes have been recorded at Mount Moulton and are either of volcano-tectonic origin or due to the movement of ice along the flanks of the volcano. The mountain is high, rising about above the ice surface on its northern flank, and located within the Flood Range; Mount Berlin lies across the Wells Saddle to the west and Kohler Dome is east of Moulton. Even farther east lie Mount Bursey, Mount Andrus, Mount Kosciuszko and Mount Kauffman, in the Ames Range.
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The oldest geological units on Lombok are from the Oligocene-Miocene, with old volcanic units cropping out in southern parts of the island. Samalas was built up by volcanic activity before 12,000 BP. Rinjani formed between 11,940 ± 40 and 2,550 ± 50 BP, with an eruption between 5,990 ± 50 and 2,550 ± 50 BP forming the Propok Pumice with a dense rock equivalent volume of . The Rinjani Pumice, with a volume of dense rock equivalent, may have been deposited by an eruption from either Rinjani or Samalas; it is dated to 2,550 ± 50 BP, at the end of the time range during which Rinjani formed. The deposits from this eruption reached thicknesses of at distance. Additional eruptions by either Rinjani or Samalas are dated 11,980 ± 40, 11,940 ± 40, and 6,250 ± 40 BP. Eruptive activity continued until about 500 years before 1257.
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The outer wall, with its short, narrow entrance and battlements The inner walls on the northern face of the castle It is situated on the top of the Sintra Mountains, where it has a panoramic view of the municipality of Sintra, and on a clear day Mafra and Ericeira. It is accessible from Santa Maria e São Miguel by a protected gate and turnstile, or across a road accessway to the Palace of Pena. The castle is located in the limits of the Sintra-Cascais Natural Park, in the north flank of the Sintra Mountains, where the slopes are at most 40% gradients, with accented or moderate variation. The Serra da Sintra, known locally, consists of an eruptive massif with an abundance of granite, sienitos, gabros and dioritos rock formations, with soils consisting of litólicos, húmicos, câmbicos, normais, de granito (Mng).
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When the first geological reconnaissance of the surrounding region was published in 1925, its author, Edwin T. Hodge, suggested that the Broken Top, the Three Sisters, and several other mountains in the area constituted the remains of an enormous collapsed volcano that had been active during the Miocene or early Pliocene epochs. Naming this ancient volcano , Hodge theorized that it had collapsed to form a caldera just as Mount Mazama collapsed to form Crater Lake. In the 1940s, Howel Williams completed an analysis of the vicinity and concluded that Multnomah had never existed, instead demonstrating that each volcano in the area possessed its own individual eruptive history. Williams' 1944 paper, titled "Volcanoes of the Three Sisters Region, Oregon Cascades", defined the basic outline of the region, though he lacked access to chemical techniques and radiometric dating.
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Since the glacier was first observed to be forming and actively flowing in the late 1980s, most scientists working on the mountain have referred to it informally as the "crater glacier". That name has been in wide use with the public (at least those who were aware of the glacier's existence) for the two decades since the glacier formed, and has appeared in several scientific publications too. A single scientific paper, the most complete published study of the glacier to date, referred to it as the "Amphitheater glacier," but that name has not been used otherwise. Despite numerous observations and publications about the growing glacier in the late 1990s and early 2000s, no move was made to give the glacier a permanent and official name until late 2004, after the current eruptive cycle began and the new dome began to split the glacier.
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Continuing heating required the water to expand further and the only way it could do so was to move the flank of the volcano. This caused the two earthquakes that were reported as occurring during the eruption along with the development of the crack. That the entrapped (within the edifice) water did not vapourise is shown by the absence of phreatomagmatic explosions except the mildly explosive eruptive activity that occurred at the Hoyo Negro vent from 12 to 22 July: steam escaping explosively from the ground is often a precursor of volcanic activity. Further evidence that vapourisation did not occur is that when Rubio Bonelli visited the rift the following day, the newly opened fissure "... Was not issuing fumes, vapour, steam, ashes, lava or other materials ..." In fact at no time during or after was steam or phreatomagmatic activity reported.
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The names of volcanic features on Io use a combination of a name derived from mythological figures from around the world related to the Sun, fire, volcanoes, thunder, or smithing, places from the Greek mythological story of Io, Dante's Inferno, or from the name of a nearby feature on Io's surface and an approved descriptive term. The descriptive term used is based on the type of feature named and how it was first discovered. Volcanoes that were first observed as an active feature from observations of a volcanic plume fit under the category of "Eruptive Center" and do not use a descriptive term, though portions of these features may have also received names that do use a descriptive term, like Prometheus Patera or Masubi Fluctus. Lava flows use the descriptive term fluctus or the plural fluctūs, e.g.
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North Sister (of the Three Sisters volcano complex) and Mount Washington mark isolated volcanic centers among the highly mafic (rich in magnesium and iron) platform of the central High Cascade arc. About 4.5 million years ago, eruption of mafic lava filled a subsiding Pliocene depression, creating the modern, mafic High Cascades. Compared to the eruptive products at and near North Sister, lava deposits at Mount Washington have a greater abundance of incompatible elements (elements unsuitable in size and/or charge to the cation sites of the minerals of which it is included.) The nearby lava dome and tuya (subglacial volcano) Hogg Rock shows more similarity to the basaltic andesite deposits at North Sister, which are poorly enriched in incompatible elements. The part of the High Cascades that extends south from Mount Jefferson to Santiam Pass includes shield volcanoes, lava domes, and cinder cones.
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Statistics place the likelihood of a major eruption in the Cascade Range at 2–3 per century. Mount Rainier is listed as a Decade Volcano, or one of the 16 volcanoes with the greatest likelihood of causing loss of life and property if eruptive activity resumes. If Mt. Rainier were to erupt as powerfully as Mount St. Helens did in its May 18, 1980 eruption, the effect would be cumulatively greater, because of the far more massive amounts of glacial ice locked on the volcano compared to Mount St. Helens, the vastly more heavily populated areas surrounding Rainier, and the simple fact that Mt Rainier is a much bigger volcano, almost twice the size of St. Helens. Lahars from Rainier pose the most risk to life and property, as many communities lie atop older lahar deposits.
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The youngest was John Boulton Young, a 13-year-old drummer boy from Sunbury in Northumberland County, Pennsylvania. Dubbed "Boltie" (or "Boulty") and described in letters home by regimental officers as the regiment's "pet," he became the 47th Pennsylvania's first casualty, succumbing to Variola (smallpox) at the Kalorama eruptive fever hospital in Georgetown, District of Columbia on October 17, 1861. According to Sunbury's Daily Item, the uniform that Young had worn during his brief service was a dark blue wool Zouave-style jacket with red trim and red wool pants [with] leather gaiters to protect his legs while marching" – a style dramatically different from the more traditional Union blues worn by other members of the regiment. Due to his small stature, Young was also given "an undersized, nonregulation drum complete with small drumsticks," which measured just "13 1/2 inches across and ... 13 inches deep.
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Frank Rutley (14 May 1842 – 16 May 1904), an English geologist and petrographer, was born in Dover on 14 May 1842. He was educated partly in Bonn, but his interest in geology was kindled at the Royal School of Mines, where he studied from 1862 to 1864. He then joined the army, and served as lieutenant until 1867, when he became an Assistant Geologist on the Geological Survey. Working in the Lake District, Rutley began to make a special study of rocks and rock-forming minerals, and soon qualified as acting petrographer on the Survey. For several years be worked in this capacity at the museum in Jermyn Street; he described the volcanic rocks of East Somerset and the Bristol district in 1876, and wrote special memoirs on The Eruptive Rocks of Brent Tor (1878) and on The Felsitic Lavas of England and Wales (1885).
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Intraplate volcanoes occur in many places of the Western United States, including along the Sierra Nevada, on the Colorado Plateau, the Basin and Range province and the Rio Grande Rift. Lunar Crater volcanic field lies within the Basin and Range province along with other volcanic fields, but in an unusually central position. Upwelling of asthenospheric mantle in response to the tectonic regime of the Basin and Range may be responsible for the eruptive activity there, although other processes have also been proposed such as mantle downwelling and compensating flow in the asthenosphere; older volcanism in the region is related to the subduction of the Farallon Plate. The Basin and Range province has had a complicated geological history and in the last 20 million years features extensional tectonics (tectonic processes involving a dilatation of the crust) represented by normal faults (faults where the downmoving blocks move in a way consistent with gravity).
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They also produced the Sahalie Falls and the Koosah Falls, as well as the long Clear Lake, which still contains branches and bark from tree debris after the eruption. The overall dense-rock equivalent (DRE) volume for the volcanic field lavas and volcanic cones is estimated to be . The Sand group has a DRE volume of , Lost Lake a DRE volume of , and Nash group a DRE volume of . Past radiometric dating gave Sand Mountain Volcanic Field's age within a 1,000 year range. More precise paleomagnetic dating suggested that the field includes at least 13 distinct eruptive units, which were generated over a short period of time (likely just a few decades) about 2,950 years ago. The Jack Pine vent, which resides at the northern edge of the field, has a distinct composition from the field's other landforms; it likely erupted about 4,000 years prior to the rest of the field.
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Hogg Rock, Three Fingered Jack, Mount Jefferson, and U.S. 20 near Santiam Pass North Sister and Mount Washington mark isolated volcanic centers among the highly mafic (rich in magnesium and iron) platform of the central High Cascades. About 4.5 million years ago, eruption of mafic lava filled a subsiding Pliocene depression, creating the modern mafic edifice of the High Cascades. Compared to the eruptive products at and near North Sister, lava deposits at Mount Washington have a greater abundance of incompatible elements (elements unsuitable in size and/or charge to the cation sites of the minerals of which it is included.) Hogg Rock shows more similarity to the basaltic andesite deposits at North Sister, which are poorly enriched in incompatible elements. The part of the High Cascades that extends south from Mount Jefferson to Santiam Pass includes shield volcanoes, lava domes, and cinder cones.
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Visual light curve for RY Sagittarii, 1988–2015, showing classic behaviour for this type of variable An R Coronae Borealis variable (abbreviated RCB, R CrB) is an eruptive variable star that varies in luminosity in two modes, one low amplitude pulsation (a few tenths of a magnitude), and one irregular, unpredictably-sudden fading by 1 to 9 magnitudes. The prototype star R Coronae Borealis was discovered by the English amateur astronomer Edward Pigott in 1795, who first observed the enigmatic fadings of the star. Only about 150 RCB stars are currently known in our Galaxy while up to 1000 were expected, making this class a very rare kind of star. It is increasingly suspected that R Coronae Borealis (RCB) stars – rare hydrogen-deficient and carbon-rich supergiant stars – are the product of mergers of white-dwarfs in the intermediary mass regime (total mass between 0.6 and 1.2 ).
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A volcanic winter is thought to have taken place around 70,000 years ago after the supereruption of Lake Toba on Sumatra island in Indonesia. According to the Toba catastrophe theory to which some anthropologists and archeologists subscribe, it had global consequences, killing most humans then alive and creating a population bottleneck that affected the genetic inheritance of all humans today. It has been suggested that volcanic activity caused or contributed to the End-Ordovician, Permian- Triassic, Late Devonian mass extinctions, and possibly others. The massive eruptive event which formed the Siberian Traps, one of the largest known volcanic events of the last 500 million years of Earth's geological history, continued for a million years and is considered to be the likely cause of the "Great Dying" about 250 million years ago, which is estimated to have killed 90% of species existing at the time.
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Smaller mudflows also formed on every side of the volcano, as well a layer of pumice and volcanic ash that reached as far as northeast; volcanic ash was detected up to east at the city of Elko, Nevada. Additionally, the lava flow on the volcano's northeastern flank was removed by this eruption, but not the similar deposit on the western flank. The eruptive output volume totaled , dwarfed by the 1980 eruption of Mount St. Helens, which had a volume of . The region on the volcano's northeastern flank destroyed by the eruptions, in area, is now known as the Devastated Area, and it along with other deposits from the volcano has been altered by erosion and regrowth of vegetation, though the vegetation in Devastated Area is sparse due to its siliceous (rich in silica), nutrient-deprived soil, which cannot sustain normal tree growth due to its lack of water retention.
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Because Newberry has had recent eruptive activity, has remained active for a long time, and has a shallow heat source feeding hot springs, it represents a source of geothermal energy. An investigation conducted by the United States Geological Survey in 1981 drilled a well in depth at a location to the east of the Big Obsidian flow, finding temperatures of under the surface there. An energy company drilled two holes with a depth of in 1995 and 1996, but they were unable to find fluids, so they lacked a mechanism to drive turbines and opted to end the project at Newberry. According to many scientists, Newberry Volcano represents the best geothermal energy candidate in the Pacific Northwest; in 2012, a deep well was built to determine whether water directed into the hole might be heated and returned to the surface in order to yield energy.
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The eruptions that produced the Emeishan Traps began 265 million years ago (Ma) or earlier. The main eruptive period is between 262 and 261 Ma, and the volcanism activities end 259 Ma. In volume, the Emeishan Traps are dwarfed by the massive Siberian Traps, which occurred, in terms of the geological time scale, not long after, at approximately 252 Ma. The Emeishan basalts covers an area of more than 250,000 km2 with thicknesses ranging from several hundred meters up to 5.5 km (the average flood basalt thickness throughout the entire region is estimated to be around 700 m), but the Emeishan traps may have initially covered an area as much as 500,000 km2. Thus the entire volume of the Emeishan basalts is estimated to be 300,000 km3. Evidence suggests that the initial volcanism of the central Emeishan Traps occurred in a deep submarine environment without any significant prevolcanic uplift.
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The most recent eruption of Mount Rinjani was in May 2010 and the most recent significant eruptions occurred during a spate of activity from 1994 to 1995 which resulted in the further development of Gunung Barujari. Historical eruptions at Rinjani dating back to 1847 have been restricted to Barujari cone and the Rombongan dome (in 1944) and consist of moderate explosive activity and occasional lava flows that have entered Segara Anak lake. The eruptive history of Rinjani prior to 1847 is not available as the island of Lombok is in a location that remained very remote to the record keeping of the era. On 3 November 1994, a cold lahar (volcanic mudflow) from the summit area of Rinjani volcano traveled down the Kokok Jenggak River killing thirty people from the village of Aikmel who were caught by surprise when collecting water from the river in the path of the flow.
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During the following years periodic seismic activity occurred, but due to the absence of monitoring equipment, the only reports are those recorded in the media. Then at about 09:00 (local time) on 24 June 1949, the Duraznero vent opened with mildly explosive activity, venting of gases, and rocks; with eruptive activity continuing in this manner until 6 July. During this phase a strong earthquake occurred on 1 July and again on 2 July with an estimated intensity of VIII on the Modified Mercalli Scale. Visits to the summit region revealed a crack about 1.5 km (~1 mile) long which extended in a northerly direction from the Hoyo Negro (Black Hole) and about 1 km (~0.5-mile) south to the Duraznero vent making a total length of about 2.5 km (~1.6-mile), (this crack is the subject of research and heated debate as to whether it indicates initial failure of the western flank – or not).
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On 8 July eruptive activity commenced at the Llano del Banco vents – about 4 km (~2.8miles) north of the Duraznero vent, as lava was erupted and flowed down the western flank. The vents opened progressively up the barranco (ravine), forming a series of en echelon (diagonally side by side), vents. On 10 July the westward flow of lava from the Llano del Banco vents reached the coast at Puerto de Naos and entered the Atlantic Ocean, forming a lava delta, the velocity is estimated at ~14 metres (approximately 46 feet) per sec. On 12 July mildly explosive activity commenced at the Hoyo Negro (Black Hole) with emissions of rocks, fumes and some phreatomagmatic activity indicating that the eruption had encountered ground waters. Activity at the Hoyo Negro ceased on 22 July, but continued at the Llano del Banco vents until 26 July. Only residual fumarolic activity and thermal emissions then occurred until 30 July when the Duraznero vent and fissure re-activated.
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One of the major problems in classifying and identifying komatiite-hosted NiS ore deposits as Kambalda type is the structural complication and overprint of metamorphism upon the volcanic morphology and textures of the ore deposit. This is especially true of the peridotite and dunite hosted low-grade disseminated Ni-Cu-(PGE) deposits such as Perseverance, Mount Keith MKD5, Yakabindie and Honeymoon Well, which occupy peridotite bodies which are at least 300m and up to 1200m thickness (or more). The major difficulty in identifying adcumulate peridotite piles in excess of 1 km as being entirely volcanic is the difficulty in envisaging a komatiitic eruptive event which is prolonged enough to persist long enough to build up via accumulation such a thickness of olivine-only material. It is considered equally plausible that such large dunite-peridotite bodies represent lave channels or sills through which, perhaps, great volumes of lava flowed en route to the surface.
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A large Edziza lava flow and the Eve and Sidas cones The fifth and final phase of eruptive activity occurred from secondary volcanic vents along the flanks of the four central volcanoes starting 10,000 years ago. This phase of activity began at a time when remnants of glacial ice were still present and continued after the glacial period. The initial flank eruptions, quenched by glacial meltwater, formed hyaloclastite tuff rings, whereas later activity created 30 small cinder cones, primarily of basaltic composition, including Mess Lake Cone, Kana Cone, Cinder Cliff, Icefall Cone, Ridge Cone, Williams Cone, Walkout Creek Cone, Moraine Cone, Sidas Cone, Sleet Cone, Storm Cone, Triplex Cone, Twin Cone, Cache Hill, Camp Hill, Cocoa Crater, Coffee Crater, Nahta Cone, Tennena Cone, The Saucer and the well-preserved Eve Cone. These cinder cones were formed no earlier than the year 700 based on the age of burnt plant stems still rooted in former soil under of loose basaltic fragments.
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No volcanic activity took place 190,000 years ago to roughly 90,000 years ago, but during the last 100,000 years, there have been at least 12 periods of eruptive activity in the Lassen volcanic center, and since 90,000 years ago, the Twin Lakes sequence has been producing mixed lavas with variable appearances and compositions, including andesite and basaltic andesite lava flows and agglutinated volcanic cones (made of fused pyroclastic rocks) located by the Lassen domefield. The Twin Lakes sequence includes construction of the Chaos Crag dome complex between 1100 and 1000 years ago and eruptions at Lassen Peak beginning in 1914. Prior to 1914, Lassen Peak likely underwent at least one explosive eruption, which created a summit crater in depth with a diameter of . Deposits from older mudflows that can be traced specifically to the Lassen dome have also been found in Hat Creek, Lost Creek, and in a region to the east of the Devastated Area.
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Moreover, a number of the potentially active Californian volcanoes reside less than from highly populated areas, and explosive eruptions could produce ash that travels for several hundred miles. In the case of signs that suggest impending volcanic activity, the United States Geological Survey has a plan in place to utilize portable monitoring instruments, deploy scientists to the area, and implement an emergency response plan developed by the National Park Service if an eruption were imminent. Although basaltic lava flows are the most common eruptive activity in the Lassen volcanic center, they could also produce more violent and thus more hazardous silicic lava flows, in addition to building additional, unstable lava domes that could collapse and spawn pyroclastic flows that could extend for several miles. Because Lassen Peak has a significant amount of snow and ice, these pyroclastic flows (or hot volcanic ash) might mix with water to form lahars (volcanically induced mudslides, landslides, and debris flows) that could destroy nearby communities.
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A reviewer for Kirkus Reviews criticized "Pornography" as predictable, but praised the title story, "Reflections of a Kept Ape", and "Dead as They Come", referring to the last of the three as "not the first story about a man in love with a mannequin, but surely both the funniest and ugliest". The reviewer wrote that "this slim collection is hardly McEwan at his best (he remains a writer of tremendous style who seems limited by his obsessions), but at the very least it reinforces his position as the Roald DaM for the sexually-eruptive 1970s.” Julian Moynahan of The New York Times wrote an unfavorable review. Moynahan praised "To and Fro" as an "elegant stylistic exercise" but panned the title story, arguing, "The see-saw relation between life and art that is implied goes back to Pater, Wilde, Mann, Yeats and a host of other writers active at the turn of the century.
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Seismic stations have been maintained on Hawaiʻi since the Observatory's inception, but these were concentrated primarily on Kīlauea, with coverage on Mauna Loa improving only slowly through the 20th century. Following the invention of modern monitoring equipment, the backbone of the present-day monitoring system was installed on the volcano in the 1970s. Mauna Loa's July 1975 eruption was forewarned by more than a year of seismic unrest, with the HVO issuing warnings to the general public from late 1974; the 1984 eruption was similarly preceded by as much as three years of unusually high seismic activity, with volcanologists predicting an eruption within two years in 1983. The modern monitoring system on Mauna Loa is constituted not only by its locally seismic network but also of a large number of GPS stations, tiltmeters, and strainmeters that have been anchored on the volcano to monitor ground deformation due to swelling in Mauna Loa's subterranean magma chamber, which presents a more complete picture of the events proceeding eruptive activity.
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October 5: Steam and ash eruption, seen from the Johnston Ridge Observatory. Mount St. Helens vented another plume of steam the next day at 12:14p.m. PDT, which was stronger than the previous steam release. A low-frequency harmonic tremor followed the steam release, which led seismologists to raise the "alert level" to the third of three levels, indicating a potential threat to life and property. Accordingly, the Johnston Ridge Observatory overlooking Mount St. Helens was evacuated; television media established their bases at Castle Lake Viewpoint about nine miles (14 km) away, while tourists moved to various locations for several miles along State Route 504. On October 3, low-frequency harmonic tremor activity began at around 3:00a.m. PDT and lasted for up to 90 minutes, which may have indicated the movement of magma beneath the mountain. The tremors were followed by a steam release at around 10:40a.m. A steam plume rises from the mountain in December 2004 Mount St. Helens' eruptive activity continued over the following days, with steam releases occurring on October 4 at 9:47 a.m.
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Because the deposits thin towards the north, and there are few signs of volcanic necks within the Ochil Hills themselves, it is thought that the eruptive centres were south of the fault, however these are buried deep beneath the Carboniferous rocks including coal measures which are found beneath the low-lying carse lands to the south. To put this in perspective, the prominent hill Dumyat which defines the western extremity of the Ochil Hills has a height of 418 metres. The nearest colliery, Manor Powis, approximately 2 km south of the fault, was approximately the same depth, in carse land that is scarcely above sea level, and was mining coal from Carboniferous strata at least many hundreds of metres above the top of the Devonian deposits. The Ochil Fault was active from the earliest part of the Carboniferous period, allowing the marine swamps in which the coal-producing vegetation flourished to be periodically overlain by layers of sand, forming sandstone, or silt, forming shale, in a number of cyclic subsidences.
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Liu used chromatography to analyze the average of volatiles of five pumice and obsidian, finding the fluorine content to be 0.0158–0.0481%. Horn and Schimincke used an ion probe to find an average fluorine content in inclusions of 0.4294%, but fluorine concentrations in matrix glass show a significant bimodal distribution into F-rich (0.3992% F) and F-poor (0.2431% F). In order not to over-estimate syn-eruptive fluorine loss, they considered this bimodal distribution of fluorine for calculating the volatile difference between matrix glass and melt inclusions (4300 ppm F). The volatile loss is approximately 300 ppm F for melt inclusion and F-rich matrix glass (64% proportion of the comenditic magma), whereas it is 1900 ppm F for melt inclusion and F-poor matrix glass (36% proportion of the comenditic magma). Horn concluded that 42 ± 11 Mt of F was released by the eruption. Guo, based on less samples (9 inclusions and 3 matrix glass), calculated that F contents in inclusions and matrix glass are 0.42% and 0.21%, respectively.
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Middle Tertiary formations found on Santa Rosa and Santa Cruz include the Vaqueros Formation, while those two islands plus San Miguel have exposures of the Rincon Formation, and Monterey Formation. Santa Rosa and San Miguel have exposures of the basaltic and dacitic San Miguel Volcanics, which include pillow structures, while the San Onofre Breccia is found on Santa Rosa, Santa Cruz, and Anacapa. Santa Rosa Island Volcanics consist mainly of basaltic breccia, which erupted about 19 Ma. San Miguel Volcanics consist of basalt and andesite flows, which erupted between 17-18 Ma. Santa Cruz Island (SCI) Volcanics on the north side of the island consist of andesitic flows and volcaniclastics, overlying the San Onofre Breccia, and dated at about 16 Ma. The eruptive center is east of Devils Peak, and juxtaposed against the west- northwest trending strike-slip Santa Cruz Island Fault to the south. These 2400 m of SCI Volcanics have been further subdivide into four members, consisting of the lowermost Griffith Canyon, followed by Stanton Ranch, Devil's Peak, and Prisoner's Harbor, the uppermost.
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His scientific papers were numerous, and he was one of the first to devote himself to the study of the microscopic structure of minerals and rocks, using sections prepared by himself. Among his papers were two on the "Greenstones" of Cornwall, one on the rocks of the mining districts of Cornwall, with others on the chemical and mineralogical changes in certain eruptive rocks of North Wales, on the constitution and history of grits and sandstones, and on concretionary patches and fragments of other rocks contained in granite—all published in the Quarterly Journal of the Geological Society of London. He also contributed to the Proceedings of the Royal Society, the Philosophical Magazine, the Chemical News, and other scientific journals. Besides a number of pamphlets, he also published a work in 1867 on the Mining and Metallurgy of Gold and Silver; a Manual of Metallurgy in 1852, on the fourth edition of which he was engaged, in collaboration with Hilary Bauerman, at the time of his death; and a Treatise on Ore Deposits in 1884.
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Mauna Loa is the largest subaerial and second largest overall volcano in the world (behind Tamu Massif), covering a land area of and spans a maximum width of . Consisting of approximately of solid rock, it makes up more than half of the surface area of the island of Hawaiʻi. Combining the volcano's extensive submarine flanks ( to the sea floor) and subaerial height, Mauna Loa rises from base to summit, greater than the elevation of Mount Everest from sea level to its summit. In addition, much of the mountain is invisible even underwater: its mass depresses the crust beneath it by another , in the shape of an inverse mountain, meaning the total height of Mauna Loa from the start of its eruptive history is about . Snow-covered Moku‘aweoweo caldera in 2016 Mauna Loa is a typical shield volcano in form, taking the shape of a long, broad dome extending down to the ocean floor whose slopes are about 12° at their steepest, a consequence of its extremely fluid lava.
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The Galapagos Islands are believed to be formed from a mantle plume which creates a hotspot of volcanic activity away from plate boundaries where islands then form above it, similar to process that has created the Hawaiian islands. Cerro Azul is at the edge of the upwelling with steep drop offs in the ocean to the West, while the sea is shallower to the east of Isabela Island. Cerro Azul is one of six coalescing volcanoes on Isabela Island: Ecuador, Wolf, Darwin, Alcedo, and Sierra Negra. Cerro Azul is shaped like a large upturned soup bowl and like the other volcanoes on Isabela Island has a large caldera its one at 4x5 km across is one of the smallest. The caldera shows evidence of collapse following eruptive episodes and reaches a depth of 450 m to 650 m below the rim of the caldera, only Wolf Volcano in the Galapagos is as deep. The volcano is 34 by 22 km at maximum and has a volume of 172 km3.
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Gérard Schneider, photo by Paolo Monti, 1961 (Fondo Paolo Monti, BEIC). Gérard Ernest Schneider (1896–1986) was a Swiss painter. A major pioneer of Lyrical Abstraction, a gestural and personal form of abstraction, along with Hans Hartung and Pierre Soulages, Gérard Schneider was shown in Paris at the Galerie Louis Carré as early as 1950. From 1955 to 1960, Schneider’s work was exhibited at the Kootz Gallery in New York where an exclusivity contract connected the artist and the American dealer Samuel Kootz. From gesture, “the shape is born, whether lyrical or dramatic, with its colour and technical means, without any reference to external nature” according to Schneider. Eugène Ionesco spoke of “the original, eruptive, richness” of his work. From nervous gesture and volcanic composition, full of tension, of the 1950s followed “the light years” from Michel Ragon’s expression, which were marked by the balance of forms reflecting each other and the explosion of colour. "Painting should be looked in the same way as music is listened to", as Schneider enjoyed saying. Musical, his work is to be understood like “an orchestra” which expresses “passion, fury, romanticism“ according to Michel Ragon.
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A cinder cone and surrounding flows on Mauna Loa To have reached its enormous size within its relatively short (geologically speaking) 600,000 to 1,000,000 years of life, Mauna Loa would logically have had to have grown extremely rapidly through its developmental history, and extensive charcoal-based radiocarbon dating (perhaps the most extensive such prehistorical eruptive dating on Earth) has amassed a record of almost two hundred reliably dated extant flows confirming this hypothesis. The oldest exposed flows on Mauna Loa are thought to be the Ninole Hills on its southern flank, subaerial basalt rock dating back approximately 100 to 200 thousand years. They form a terrace against which younger flows have since banked, heavily eroded and incised against its slope in terms of direction; this is believed to be the result of a period of erosion because of a change in the direction of lava flow caused by the volcano's prehistoric slump. These are followed by two units of lava flows separated by an intervening ash layer known as the Pāhala ash layer: the older Kahuka basalt, sparsely exposed on the lower southwest rift, and the younger and far more widespread Kaʻu basalt, which appear more widely on the volcano.
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