Lahar is described as flow of pyroclastic material and slurry.
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But these air cushions might not just describe pyroclastic flows.
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The pyroclastic flow -- dense and rocky -- travels at the bottom.
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"You will not survive a pyroclastic flow," Dr. Segall said.
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Pyroclastic flows swallowed the rural town of San Miguel Los Lotes.
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Pyroclastic flows, it should be noted, are completely different than lava flows.
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Fast-moving pyroclastic flows of gas, ash and lava engulfed nearby villages.
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Sunday, officials have said, unleashing a hot pyroclastic flow that destroyed nearby towns.
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Later that month, several people were killed by pyroclastic flows from the volcano.
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Every last crater, ridge, and pyroclastic deposit can be seen in high-resolution.
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Pyroclastic flows can race down a volcano at hundreds of kilometers per hour.
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Most PDCs separate into a pyroclastic flow and a surge soon after forming.
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Nearby areas were smothered in 363 feet (about 100 meters) of pyroclastic flow deposits.
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Pyroclastic flows from that eruption caused a tsunami that killed more than 35,000 people.
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And they simply aren't capable of producing such extremely fast, powerful pyroclastic flows, said Phoenix.
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They tend to have frequent explosive eruptions featuring a mix of lava and pyroclastic material.
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Rather, it was the pyroclastic flow—a dense, fast-moving cloud of hot gas and fragments.
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Which is currently and instantly releasing all the stored volcanic gases in the ultimate pyroclastic eruption.
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And nearly 200 people remain missing in villages buried by thick ash, debris and pyroclastic flow.
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"For people affected by the pyroclastic flow and ash, those clean clothes are vital," Tollefsrud said.
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Mayon, the country's most active volcano, has been spewing ash, lava, and pyroclastic material since Jan.
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The researchers explored the question using an experiment called PELE, the Pyroclastic flow Eruption Large-scale Experiment.
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But eventually, it becomes unstable and collapses under its own weight in a pyroclastic density current (PDC).
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Other: This category covers just about everything else, from pyroclastic cones to lava domes and other varieties.
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Officials said the volcanic eruption still presented a danger and could cause more mud and pyroclastic flows.
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Eight people are dead in California, tens of thousands evacuated, smoke and pyroclastic clouds are visible from space.
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This mix, known as pyroclastic flow, can race down a volcano at hundreds of kilometers per hour. 5.
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Most of the people were either flash-heated to death from the pyroclastic flow or died from asphyxiation.
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Pyroclastic flows accompanied the Mount St. Helens eruption in one case, and buried the city of Pompeii in another.
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Experts are concerned that Fuego—one of Central America's most active peaks—may erupt again, producing another pyroclastic flow.
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That fast-moving pyroclastic flows of gas and ash killed scores of people during the eruption is well documented.
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Here, the destructive path of a pyroclastic flow — which can travel hundreds of miles per hour — can be seen.
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CNN meteorologist Ivan Cabrera says the pyroclastic flow on Sunday was over 1,800 degrees Fahrenheit (about 1,000 degrees Celsius).
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Dr. Nomikou said that other surveys show deposits of pyroclastic material up to 200 feet thick just off Santorini.
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According to the U.S. Geological Survey, pyroclastic flows are impossible to outrun, and contain a variety of deadly hazards.
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It would have descended on a hapless White House staff like a superheated pyroclastic flow from a presidential Pinatubo.
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A prevailing hypothesis is that their blood and brains were vaporized by the extreme heat of the pyroclastic flow.
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"If you're in the path of a pyroclastic flow, you're dead," volcanologist Jess Phoenix said in an interview last week.
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In Guatemala, pyroclastic flow from Sunday's eruption topped 1,800 degrees Fahrenheit (about 1,000 degrees Celsius), CNN meteorologist Ivan Cabrera said.
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Much of the resort complex is now seared by the pyroclastic flows -- they cut the golf course links in half.
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The pyroclastic flow follows the topography it encounters, quickly becoming channeled in pre-existing valleys and deepening them through erosion.
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It was a pyroclastic flow that did so much damage in 1980, when Mt. St. Helens erupted in Washington State.
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Cellphone video shot by bystanders and local news media on the scene captured the pyroclastic flow rapidly engulfing the landscape.
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Volcanoes on this naughty list aren't necessarily the ones voted most likely to blow; instead, they're potentially volatile volcanoes within populated regions that are capable of producing lava flows, ash falls, pyroclastic flows (fast-moving plumes of rock, ash, and volcanic gases), and lahars (similar to pyroclastic flows, but containing mud and other volcanic debris), and other volcanic blights.
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Do the pyroclastic flows race out at the same speeds and are these flows the same mix of hot gasses and ash?
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A few pyroclastic flows have also been generated by this new activity, mostly heading down drainages to the northwest of the volcano.
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The kind of convective cloud we do not want to see: a pyroclastic flow - from yesterday's major eruption of Fuego volcano, Guatemala.
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The authors reached some unexpected results: Supervolcanoes destroy slowly, oozing molten rock across the landscape rather than blasting it in pyroclastic storms.
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And yet, pyroclastic flows can travel for tens to hundreds of miles down slopes with angles of just 8 to 9 degrees.
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These "pyroclastic flows" hit much faster, more lethal speeds than lava, dragging trees and giant rocks down onto villages in their path.
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Tremors continue and a pyroclastic flow, a mix of ash, rock and volcanic gases, runs 2 kilometers (1.2 miles) from the crater.
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As the pyroclastic flow blasted the beach, debris would have piled up at the boathouse exits, trapping dust, gases and people within.
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Dr. Mazariegos said the eruption was the first in Guatemala to release such high volumes of pyroclastic flow and its accompanying gases.
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It set off lahars—fast-flowing mixtures of rock, debris, ash and water—and red-hot pyroclastic flows, which buried several nearby villages.
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In 1963, pyroclastic flows of lava and rocks poured out of the volcano, killing more than 1,000 people and razing dozens of villages.
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"If you witness a pyroclastic flow, run in the opposite direction as quickly as possible," the US Geological Survey notes on its website.
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These pyroclastic flows travelled east and south at over 60 km/hr, wiping out several villages and causing the death of over 1000 people.
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Agung's last eruption in 1963 killed more than 1,000 people and razed several villages by hurling out pyroclastic material, hot ash, lava and lahar.
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The village of San Miguel Los Lotes was swallowed by the volcano's pyroclastic flow — a current of gases, sand, ash, rocks and tree trunks.
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On Friday, Pyroclastic will release "Diatom Ribbons," Ms. Davis's latest album and the one most likely to catch on with a broad jazz audience.
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He said pyroclastic flows can tumble down a volcano at hundreds of kilometers per hour -- way faster than what people and even cars could outrun.
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Firefighters said they had seen some people who were trapped, but roads were cut by pyroclastic flows and they had been unable to reach them.
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The Philippine Institute of Volcanology and Seismology said that similar pyroclastic flows, tremors and streams of lava had all been detected several times on Thursday.
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In 1963, an eruption of Agung killed more than 1,000 people and razed several villages by hurling out pyroclastic material, hot ash, lava and lahar.
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"Explosive volcanic super-eruptions expel magma volumes of several hundred cubic kilometres or more and generate particle-gas flows called pyroclastic density currents," the geologists write.
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These gruesome deaths were a result of a powerful pyroclastic surge, which is a molten blast of gas and rock, that swept over this waterfront refuge.
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"The bigger issue with pyroclastic flows is they can be turned into volcanic mudflows (lahars) when the loose debris mixes with rain/river waters," he said.
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More pyroclastic flow -- the name for the nasty mix of ash, rock and volcanic gases -- is possible in coming days, the country's disaster relief agency said.
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While Pompeii was consumed by ash, Herculaneum was done in by a pyroclastic flow — a fast-moving, dense, extremely hot surge of ash, gas and rock.
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The data showed that people in the boathouse were exposed to temperatures of about 500 degrees Fahrenheit — far from the maximum temperatures pyroclastic flows can reach.
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The team took samples of sediments and water in the vicinity of the volcano and recovered coal-like black pyroclastic material, the NIO said in the statement.
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Populations closer to the volcano bear the full brunt of pyroclastic flows (likely the biggest killer), heavy ash fall, and lava flows (although they aren't that deadly).
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"These clouds are analogous to the huge pyroclastic clouds that form from a major volcanic explosion, or from the ground explosion of a nuclear bomb," said Burt.
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Sutopo Purwo Nugroho, a spokesman for Indonesia's national disaster agency, also warned of the dangers of lahars, volcanic mudflows made up of water, rocks and pyroclastic materials.
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The Mount St. Helens eruption also ejected pyroclastic flows, which reduced hundreds of square miles (km) to wasteland, and killed nearly 60 people and thousands of animals.
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A series of blasts since have spewed more deadly, fast-moving pyroclastic flows down the slopes, but have not caused more casualties since authorities have evacuated most residents.
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"Currently the volcano continues to erupt and there exists a high potential for (pyroclastic) avalanches of debris," said Eddy Sanchez, director of the country's seismology and volcanology institute.
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The debris was left by scorching avalanches of newly-formed rock and gas — known as pyroclastic flows — which, when erupted, measured some 1,800-degrees Fahrenheit, according to NASA.
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It can help you understand the mysteries of the Universe, but it won't stop your near-instant death if you're standing in the way of a pyroclastic flow.
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Dramatic video showed a fast-moving lahar, or flow of pyroclastic material and slurry, slamming into and partly destroying a bridge on a highway between Sacatepequez and Escuintla.
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Pyroclastic flows can travel at speeds of several hundred miles an hour down slopes, so there was enough lava and ash, moving quickly enough, to spawn a tsunami.
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The charred bodies of victims laid on the steaming, ashen remnants of a pyroclastic flow as rescuers attended to badly injured victims in the aftermath of the eruption.
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The researchers discovered that the bodies had not been exposed to the high temperatures expected with the volcano's pyroclastic flow, or massive cloud of toxic gas and material.
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GUATEMALA CITY, June 4 (Reuters) - Guatemala's disaster agency said on Monday there had been a new pyroclastic flow from Guatemala's Fuego volcano that violently erupted on Sunday, killing 25.
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"This debate is not just academic; an understanding of the mechanisms by which pyroclastic flows propagate is essential to accurately forecast related hazards at active volcanoes," the study cautions.
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Stone might have been doorjamb But there he was hit by the massive stone block -- perhaps a doorjamb -- possibly hurled at him by the force of the pyroclastic flow.
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"In themselves, the pyroclastic glasses from the Moon are complicated volcanic rocks and the cause of hydrogen and nitrogen enrichment in these samples is still controversial," Day told Gizmodo.
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When they erupt, they produce piles of broken volcanic debris (pyroclastic material) and the cone is filled with kimberlite breccia made from magma, xenoliths, and anything else in the way.
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Pyroclastic flows are searing-hot mixtures of volcanic material and gas that travel explosively down the slopes of volcanoes, sometimes traversing tens of miles at hundreds of miles per hour.
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A possible pyroclastic flow -- characterized by a rapid movement of hot lava blocks, pumice, ash and gas along volcanic slopes -- could reach up to three kilometers (13 miles), Solidum said.
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Volcanoes can produce a host of lethal hazards, including lava flows, tsunamis, volcanic mudflows, avalanches, flying rocks and pyroclastic flow – a mix of hot lava fragments, ash pumice and volcanic ash.
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Three villages near the volcano were evacuated due to the potential pyroclastic flow and ash hazard from these eruptions, which has been producing ash plumes that reach 4 kilometers (~13,000 feet).
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But now archaeologists, who previously thought the man had been crushed by a flying boulder while fleeing Mount Vesuvius in 70 A.D., believe he died from asphyxiation from the pyroclastic flow.
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The agency warned of potential hazards including pyroclastic flows — a mix of hot gases, lava fragments and ash — that the volcano could project up to six miles in a few minutes.
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Mariton Bornas, chief of volcano monitoring and eruption at PHIVOLCS said residents within the immediate radius would be at risk of tremors, fissures and the threat of a sudden pyroclastic flow.
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Those still within or returning to the immediate dangerous zone within a 14-kilometer (8.7 miles) radius around the volcano risk tremors, fissures and the threat of a sudden pyroclastic flow.
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In a media briefing Monday, the agency's director Renato Solidum warned that this eruption could be similar to that of 2001, which featured pyroclastic flow, according to CNN affiliate CNN Philippines.
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That's quite the relief: pyroclastic flows, on average, travel at 5383 miles (128 kilometers) per hour, and their tumbling caches of gas and ash can reach temperatures of 22,214°F (700°C).
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The explosion also triggered a deadly pyroclastic flow—a hot, fast-moving plume of rock and gas—that engulfed farms, streets, cars, and entire homes at the bottom of the southern slope.
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"The volcano is composed of intercalated pyroclastic deposits and lava flows and rests on Mesozoic granitic rocks of the Alaska-Aleutian Range batholith," the Alaska Volcano Observatory describes in a post online .
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This assumption is the source of an ongoing debate between those that favor the intuitive model of quick, billowing pyroclastic flows and those that favor a model involving sluggish, very dense flows.
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"This eruption at Fuego was explosive, sending hot debris down the steep sides of the volcano to make the pyroclastic flows," said Erik W. Klemetti, associate professor of geosciences at Denison University.
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She had been on a sailing boat near the volcano when it erupted at around 10:17 local time and captured the boat's slim escape from the pyroclastic flow with her phone.
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KRIS DAVIS "Duopoly" (Pyroclastic) Ms. Davis, a pianist of investigative instinct, digs in separately with eight worthy partners, including the clarinetist Don Byron, the drummer Marcus Gilmore and the guitarist Julian Lage.
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A similar, extremely violent eruption from Fuego volcano in Guatemala this week killed more than 100 people as it ejected deadly super-heated "pyroclastic" flows of lava and ash through nearby towns.
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Access to the site is difficult, as remnants of the pyroclastic flow cover several roads leading into the area The Fuego volcano is located about 25 miles (40 km) south of Guatemala City.
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The movement of these rocks indicates that the pyroclastic material must have been dense and fluid-like for the simple reason that a less dense, gaseous flow would have just whooshed around them.
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In pictures: Guatemala volcano erupts By contrast, Kilauea produces lava (or sticky, molten rock) that typically creeps along at maybe hundreds of meters per hour -- not nearly as fast as devastating pyroclastic flow.
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Perhaps the scariest consequence of an eruption is a combination of all of the above in a phenomenon known as pyroclastic flow, a fast-moving mix of lava, rock, ash, and toxic gas.
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Guatemala&aposs seismology and vulcanology institute said the new lahar — a flow of mud, debris, water and pyroclastic material — was fed by rains and tore down trees as it swept through ravines and gullies.
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If you find yourself in a pyroclastic flow — like the people of Pompeii in 79 AD — you'll likely suffocate to death or be crushed by a flying boulder (like this poor dude in Pompeii).
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Despite the terrors posed by pyroclastic clouds and red hot lava, Mr. Adra said there were some things he feared more than the mountain, which has nurtured his family's fields and trees for generations.
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Lava flows are molten rock, often oozing like syrup, whereas pyroclastic flows are a hot mess of exploded magma that has rapidly hardened into a range of particles, from ashy volcanic dirt to large rocks.
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From the brief, crumbling percussion of the title track to the nearly nine minutes of cut up sound of "Welcoming Pyroclastic Eradication," the album displays great variety without feeling like a collection of loose ends.
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The authors of the new study, led by Pierpaolo Petrone from the Federico II University Hospital in Naples, Italy, say many of Vesuvius' victims were killed before the subsequent ash-filled pyroclastic flows reached them.
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"Currently the volcano continues to erupt and there exists a high potential for (pyroclastic) avalanches of debris," the disaster agency said late Sunday via Twitter, quoting Sanchez, the director of the seismology and volcanology institute.
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Volcan de Fuego, which means "Volcano of Fire," exploded on Sunday in its most devastating eruption in more than four decades, showering ash on a wide area and sending rapid pyroclastic flows through nearby towns.
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Photo: C.G. Newhall, USGSScientists think they've figured out how pyroclastic flows, fast-moving bringers of death during volcanic events, can travel such incredible distances and speeds despite the friction between the volcanic material and the ground.
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Lahars are usually cooler than pyroclastic flows — they occur sometime after the eruption, when the ash has settled on the ground — but they can be extremely destructive and deadly, burying houses and people in their path.
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"Our individuals were in these kind of sealed, trapped stone oven-type things, whereas his individual was in a regular building — much more exposed and much more directly affected by the pyroclastic flow itself," he said.
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One of these, the Silver Creek caldera near the intersection of California, Nevada, and Arizona, is the subject of a new study published in Nature Communications exploring the likely movements of pyroclastic flows following a supervolcanic eruption.
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Similarly he shows us footage of Katia and Maurice Krafft, the French volcanologist couple who, after decades of famously filming flows and eruptions startlingly up close, died in a pyroclastic flow on Japan's Mount Unzen in 1991.
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It previously said 197 people had gone missing since the eruptions of dust, ash and super-heated gas known as pyroclastic flows that began on June 3 at the Fuego volcano, its strongest activity in four decades.
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Mount Ulawun on PNG's northeastern island of New Britain exploded suddenly on Wednesday, shooting an ash column 18 km (11.18 miles) into the air, while nearby Manam erupted on Friday, sending dangerous pyroclastic flows down its slopes.
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It's never known exactly what will happen after a pyroclastic flow, but scientists will be measuring tremors in the area and other activity on the mountain to determine if the volcano might continue to erupt, or settle down.
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"The amount of water in a given glass bead is not very much, but the size of some of the pyroclastic deposits is huge, so you have a lot of material to work with and process," Milliken said.
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The result of that event can be seen now as the Peach Spring Tuff, a 32,000 square-kilometer expanse of pyroclastic rock stretching across the southwestern United States from near Barstow, California to the Grand Canyon in Arizona.
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Unlike the Hawaii volcano, which has destroyed homes with slow-moving lava, the Fuego volcano unleashed fast-moving pyroclastic flow -- a highly dangerous mix of ash, rock and volcanic gases that can be much more lethal than lava.
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This activity produced some pyroclastic flows that swept down the southeastern sides of the volcano, along with some lahars (volcanic mudflows) that headed down some of the rivers that come off of Hood, like the Sandy River (see below).
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The Mayon volcano has been placed just one notch below the highest alert level of 5 since Monday, when it spewed more lava, ash and a mixture of gases, rock debris and water that scientists call "pyroclastic density currents".
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The common response is that everyone within hundreds of kilometers of the volcano would be killed almost instantly thanks to the fast moving pyroclastic flows that can rush outward from the caldera volcano for more than 150 kilometers (~100 miles).
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Research published Tuesday, including seafloor surveys, suggests that it was likely caused by huge amounts of hot ash and lava spewing from the volcano — what volcanologists call pyroclastic flows — and pouring down its slopes into the water at high speed.
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But the two eruptions that have occurred so far at the Fuego volcano near Guatemala City have been explosive, creating pyroclastic flows — fast-moving, searingly hot clouds of volcanic ash and gases — that have killed more than 100 people so far.
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His brain, said Pier Paolo Petrone, a forensic anthropologist at the University Federico II of Naples and an author of the study, turned to glass as a result of the high heat from the pyroclastic flow, and the victim's skull exploded.
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Ballistic fragments of magma could be violently expelled from the volcano, pyroclastic flows -- fast-moving currents of hot gas and volcanic matter -- could swallow anything in its path, and the volcano's slope slumping into the surrounding lake could create a volcanic tsunami.
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Pressure continued build until weeks later, when a massive explosion occurred:The sub-plinian eruption was so strong, it was estimated that the top 100 m had been blown off, creating an eruption column almost 10 km high, which collapsed to form devastating pyroclastic flows.
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Over the next few hours, the remaining inhabitants of Pompeii, including those living in the nearby settlements of Herculaneum, Stabiae, and Oplontis, were overwhelmed by avalanches of gas and dust, known respectively as hot surge clouds and pyroclastic flows, pouring down quickly from the mountain.
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Then there's the pyroclastic flows, which are the apocalyptic clouds of gases, rocks, and other volcanic debris that travel at speeds higher than 50 miles per hour (80 km/h) and at temperatures between 390 and 1,300 degrees Fahrenheit (200 to 700 degrees Celsius).
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While Hawaii's Kilauea's volcano has produced extremely hot and relatively slow moving lava flows, which have engulfed hundreds of structures but allowed people to evacuate, Guatemala's Fuego ejected much more dangerous pyroclastic flows, which kill everything in their path because they travel so fast and so far.
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And she has stepped up her work as an impresario and educator: She recently formed a nonprofit organization, which now houses her record label, Pyroclastic Records, and this fall she took on a leadership position at Berklee College of Music's new Institute of Jazz and Gender Justice.
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People who were killed by the ash-filled pyroclastic flows were exposed to temperatures around 200 to 250 degrees C (400 to 480 degrees F); as their bodies burned, their muscles contracted, resulting in a final "pugilistic" body posture in which their toes and fingers were curled inwards.
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As for Mount Kilauea in Hawaii, it's not on the IAVCEI list because it's not considered a major threat to human life; Kilauea's oozing lava and toxic gases are certainly inconvenient, but it's not terribly dangerous compared to volcanoes that can expel huge volumes of ash and generate dangerous pyroclastic flows.
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When a volcano erupts, it might take out some neighboring towns and mess with air traffic, but a supervolcano—a volcano that ejects material (ejecta) on the order of quadrillions of kilograms—can be expected to spread pyroclastic flows for hundreds of miles and dump ash even further out than that.
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"The new results from Milliken and Li show that the water is widespread, found in numerous pyroclastic deposits across the lunar surface, suggesting that the lunar mantle has significant amounts of water, not just in a couple of weird pockets," said Sarah Noble, program scientist at NASA Headquarters in Washington.
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"The individual in the photo is an adult man, killed by the hot pyroclastic surge (hot gas and ash cloud which killed most of the population living around Mount Vesuvius), with both arms and legs flexed due to the heat," Pier Paolo Petrone, a volcano expert based in Italy, told the Daily Dot.
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" With rock fragments ranging in size from ash to boulders that travel across the ground at speeds typically greater than 80 km per hour (50 mph), pyroclastic flows knock down, shatter, bury or carry away nearly all objects and structures in their path," the USGS says on a website detailing the phenomena.
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She puts it front and center on "Duopoly," an album of duets with partners including the guitarists Bill Frisell and Julian Lage, the saxophonist Tim Berne, the clarinetist Don Byron, and the pianist Craig Taborn — with whom she'll promote the album with a cross-country, two-piano tour that reaches Roulette in Brooklyn on Oct. 1073. Pyroclastic. Sept. 1063.
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Take, for example, the soft shades of green shot through "Stephanie - 1966 Suzuki Bearcat B105p 118cc," or how hot mist of the pyroclastic flow of the burnout in "Melissa - 1975 Honda CB400" echoes in the pattern of her plaid shirt, the distress of her denim jeans, and the gleaming rubber of her boots, tires, and seat.
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The Italian referendum remains a potential flashpoint and consequently the single currency has now moved from "under threat" to "almost certainly terminal and probably within the next 12 months" The volcanic lava has been bubbling for some time but the pyroclastic flows are getting harder to dodge because of the sheer scale of issues also piling up in Europe and China.
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The active volcano is 72 kilometers (45 miles) away from Bali's tourist destination, Kuta, reports the AP.The aftermath of the 1963 eruption (AP)Agung's 1963 eruption was catastrophic—its staggering death toll came from pyroclastic flows, 400 to 1000 degree Fahrenheit clouds of gas, rock, and lava moving at speeds faster than 50 miles an hour that buried and burned everything in their path.
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A new excavation at the site unearthed the skeleton of a man who was crushed by a large block of stone while attempting to flee the eruption in 79 A.D. In a Facebook post on Tuesday, officials explained that the man's body had been "hurled back" by the force of the volcano's pyroclastic flow — a mix of hot lava fragments, ash pumice and volcanic ash.
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