ROME (Reuters) - Flood-tides in Venice hit their highest level in more than 19663 years this week, inundating parts of the lagoon city under almost two meters of water and raising fears of irreparable damage to historic treasures including Saint Mark's Basilica.
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SeaGen generator weighed . each driving a generator through a gearbox like a hydro-electric or wind turbine. These turbines have a patented feature by which the rotor blades can be pitched through 180 degrees allowing them to operate in both flow directions – on ebb and flood tides. The company claims a capacity factor of 0.59 (average of the last 2000 hours).
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Corryvreckan whirlpool. The Corryvreckan is a narrow strait between the islands of Jura and Scarba, in Argyll and Bute, on the northern side of the Gulf of Corryvreckan, Scotland. It is the third-largest whirlpool in the world. Flood tides and inflow from the Firth of Lorne to the west can drive the waters of Corryvreckan to waves of more than , and the roar of the resulting maelstrom, which reaches speeds of , can be heard away.
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The influx of water from the ocean changes the salinity of the estuary, creating a salt intrusion that has been estimated to reach as far as 21.8 km (13.5 mi) upriver. Daily tidal changes affect estuary mixing and stratification. Flood tides coming from the ocean bring coastal nutrients like nitrogen and phosphorus into the estuary. During mixing events, the Yaquina Bay estuary experiences changes in gradients for salinity, concentration of chemical species, and suspended sediment, which in turn influences biological productivity.
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Huge barques (sailing ships) came up the river on flood tides to collect the wood, some of which would be taken to Australia and be made into butter boxes. After the scrub and kahikatea had been cleared farming was taken up and the farmers needed everything from food to animals and boats and the rivers carried it all in. In pioneer days the rivers were the lifelines of the Hauraki Plains, but as roads improved and bridges were built the need for river transport diminished.
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The turbine drag forces are therefore transmitted through a bearing system linking the fixed and rotating parts of the buoy. A slip ring power export swivel is located in the buoy so that twist is not imparted into the umbilical cable that takes the power from the midwater buoy to the seabed. A subsea power export cable links the umbilical’s seabed connection point to the shore. With the weather-vaning hull design and rotational midwater buoy, Evopod generates electricity with both the ebb and flood tides by always pointing into the tide’s direction of flow.
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Also, jellyfish populations (including the egg-yolk jelly) are on the rise in degraded areas as a result of increased tolerance to detrimental factors. Additionally, jellyfish play a large role in the food web and can serve as indicators of ecosystem structure and function; The larger the jellyfish population, the greater the negative impact on ecosystem services. The fried egg jellyfish typically moves faster during the day and swims fastest during flood tides. This jellyfish undergoes vertical migrations that span the water column throughout short and long time frames.
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The larvae drift in the plankton and metamorphose after about 8 to 10 weeks, dependent on temperature, at which time they settle in the intertidal zone of sandy beaches. The larvae exhibit what is sometimes called semiactive tidal transport. As the larvae cannot swim against the prevailing currents, they make use of their ability to alter their vertical position in the water column to ensure they are transported to suitable habitat. On incoming or flood tides (water level is rising), the larvae move up into the water column and are thus transported towards land.
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Some organisms have been found to move with the tidal cycle. A study looked at the abundance of a species of small shrimp, Acetes sibogae, and found that they tended to move further higher in the water column and in higher numbers during flood tides than during ebb tides experiences at the mouth of an estuary. It is possible that varying factors with the tides may be the true trigger for the migration rather than the movement of the water itself, like the salinity or minute pressure changes.
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Eraclea Mare is known for its pinewood and the "Lagoon of the Dead" (Venetian language: Laguna del Mort). The Lagoon, an unusual natural formation, was caused by the overflowing of the Piave river in 1935, whose bed was modified in its last stretch after a large flood. The Lagoon stretches between the Eraclea's Lido and the mouth of the Piave river and it is a sea- lagoon, being supplied with water only by the flood-tides. Still uncontaminated, the Mort is characterized by shallow and calm waters with a sandy and muddy seabed, rich in phytoplankton.
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Bull Wall Bridge A wooden bridge, the first Bull Bridge, was erected in 1819 to facilitate the construction of the actual stone wall, based on a design by Ballast Board engineer, George Halpin. Started in 1820, the wall was completed in 1825, at a cost of 95,000 pounds. The total length of the wall is , and there are no parapets. The majority of the wall stands clear of even flood tides, and has a paved surface, but the last stage is in the form of a breakwater, submerged at high tide; the upper surface of this part is not smoothed.
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Matching fragments of Aëtius in pseudo-Plutarch and Stobaeus Downloadable Internet Archive. Diels includes two matching fragments of Aëtius' Placita, one from Pseudo-Plutarch Epitome Book III Chapter 17 often included in Moralia and the other from Stobaeus' Extracta Book I Chapter 38 [33]. attribute the flood tides ( plēmmurai) to the "filling of the moon" ( plērōsis tēs sēlēnēs) and the ebb tides ( ampōtides) to the "lessening" ( meiōsis). The words are too ambiguous to make an exact determination of Pytheas' meaning, whether diurnal or spring and neap tides are meant, or whether full and new moons or the half- cycles in which they occur.
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He explains that the tide "deserts these shores in order to be able all the more to be able to flood other [shores] when it arrives there" noting that "the Moon which signals the rise of tide here, signals its retreat in other regions far from this quarter of the heavens". Medieval understanding of the tides was primarily based on works of Muslim astronomers, which became available through Latin translation starting from the 12th century. Abu Ma'shar (d. circa 886), in his Introductorium in astronomiam, taught that ebb and flood tides were caused by the Moon.
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As the flood tide enters the narrow area between the two islands it speeds up to and meets a variety of seabed features including a deep hole and a rising pinnacle. These features combine to create whirlpools, standing waves and a variety of other surface effects. The Corryvreckan is the third largest whirlpool in the world, and is on the northern side of the gulf, surrounding a pyramid-shaped basalt pinnacle that rises from depths of at its rounded top. Flood tides and inflow from the Firth of Lorne to the west can drive the waters of Corryvreckan to waves of more than , and the roar of the resulting maelstrom can be heard away.
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Natural calamities, such as floods, tropical cyclones, tornadoes, and tidal bores—destructive waves or floods caused by flood tides rushing up estuaries—ravage the country, particularly the coastal belt, almost every year. Between 1947 and 1988, 13 severe cyclones hit Bangladesh, causing enormous loss of life and property. In May 1985, for example, a severe cyclonic storm packing winds and waves high swept into southeastern and southern Bangladesh, killing more than 11,000 persons, damaging more than 94,000 houses, killing some 135,000 head of livestock, and damaging nearly of critically needed embankments. Flooding after the 1991 Bangladesh cyclone Annual monsoon flooding results in the loss of human life, damage to property and communication systems, and a shortage of drinking water, which leads to the spread of disease.
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There is always some flow from the river into the bay. However, the lower Ipswich and Plum Island Sound, as well as the lower four other rivers flowing into it, and the much larger Merrimack River to the north, are all tidal estuaries, so the water is brackish from mixing ocean born saltwater inland during flood tides, and the lands immediately along the banks, where not inundated some of the time, are nonetheless saturated by brackish water and support only hearty plants capable of tolerating the waters such as salt marsh hay. High tides cover all of Great Marsh and the flood plains of the lower rivers. Low tides uncover the mud flats, reducing the deep channels to small streams some often small enough one can hop across to fish elsewhere.
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Between autumn and early spring, the city is often threatened by flood tides pushing in from the Adriatic. Six hundred years ago, Venetians protected themselves from land-based attacks by diverting all the major rivers flowing into the lagoon and thus preventing sediment from filling the area around the city. This created an ever-deeper lagoon environment. In 1604, to defray the cost of flood relief, Venice introduced what could be considered the first example of a "stamp tax". When the revenue fell short of expectations in 1608, Venice introduced paper, with the superscription "AQ" and imprinted instructions, which was to be used for "letters to officials". At first, this was to be a temporary tax, but it remained in effect until the fall of the Republic in 1797.
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As part of the effort to get the Biafran leadership to change its mind, the Federal government placed a shipping embargo on the territory."Kirk-Greene, The Genesis of the Nigerian Civil War (1975), p. 6. "The final high water, and the greatest of flood tides, of this phase of Gowon's leadership came in May 1967 with his Decree – and only a no-nonsense, no-referendum military government could have effected overnight such a fundamental reversal of half a century of Nigeria's political history and administrative thinking – to replace the four Regions by twelve States. Whether Decree No. 14 was designed to forestall secession (would-be Biafra was now to consist of 3 states instead of the Eastern Region, two of them mischievously emphasising the East's long-contained minorities problem of Ibibio/Efik discontent and Calabar-Ogoja-Rivers separatism, and the third a landlocked, oil-less, overpopulated Ibo enclave) or whether it pushed Ojukwu into the final defiance of declaring a secessionist Republic remains a matter of argument.
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