A tsunami (Japanese Japanese (日本語, Nihongo?, [nihoŋɡo] ) is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic (or Japanese-Ryukyuan) language family. There are a number of proposed relationships with other languages, but none of them has gained unanimous acceptance. Japanese is an: 津波 [tsɯnami], lit. 'harbor wave';[1] English pronunciation: /(t)suːˈnɑːmi/ (t)soo-NAH-mee) or tidal wave is a series of water waves (called a tsunami wave train[2]) caused by the displacement of a large volume of a body of water, usually an ocean, but can occur in large lakes A tsunami is defined as a series of water waves caused by the displacement of a large volume of a body of water, such as an ocean. This is misleading as destructive water waves are not restricted to the ocean, in the case of this article the body of water being investigated will be a lake rather than an ocean. Tsunamis in lakes are becoming. Tsunamis are a frequent occurrence in Japan; approximately 195 events have been recorded.[3] Due to the immense volumes of water and energy involved, tsunamis can devastate coastal regions.
Earthquakes An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. Earthquakes are measured with a seismometer; a device which also records is known as a seismograph. The, volcanic eruptions During a volcanic eruption, lava, tephra , and various gases are expelled from a volcanic vent or fissure and other underwater explosions An underwater explosion, also known as an UNDEX, is an explosion beneath the surface of water. The type of explosion may be chemical or nuclear. They are categorized in accordance with their depth beneath the water's surface, because this has a strong influence on their effects (including detonations of underwater nuclear devices A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter; a modern thermonuclear weapon weighing little more than a thousand kilograms can produce an explosion), landslides A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments. Although the action of gravity is the primary driving force for a landslide to occur, there are other contributing and other mass movements Mass wasting, also known as slope movement or mass movement, is the geomorphic process by which soil, regolith, and rock move downslope under the force of gravity. Types of mass wasting include creep, slides, flows, topples, and falls, each with its own characteristic features, and taking place over timescales from seconds to years. Mass wasting, meteorite ocean impacts or similar impact events An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Impact events have been a plot and background element in science fiction since knowledge of real impacts became established in the scientific mainstream, and other disturbances above or below water all have the potential to generate a tsunami.
The Greek Ancient Greece is the civilization belonging to the period of Greek history lasting from the Archaic period of the 8th to 6th centuries BC to 146 BC and the Roman conquest of Greece after the Battle of Corinth. At the center of this time period is Classical Greece, which flourished during the 5th to 4th centuries BC, at first under Athenian historian Thucydides Thucydides (Greek Θουκυδίδης, Thoukydídēs) was a Greek historian and author of the History of the Peloponnesian War, which recounts the 5th century BC war between Sparta and Athens to the year 411 BC. Thucydides has been dubbed the father of "scientific history" because of his strict standards of evidence-gathering and was the first to relate tsunami to submarine earthquakes A submarine, undersea, or underwater earthquake is an earthquake that occurs underwater at the bottom of a body of water, especially an ocean. They are the leading cause of tsunamis. The magnitude can be measured scientifically by the use of either the Richter scale or the Mercalli scale,[4][5] but understanding of tsunami's nature remained slim until the 20th century and is the subject of ongoing research. Many early geological Geology is the science and study of the physical matter and energy that constitute the Earth. The field of geology encompasses the study of the composition, structure, properties, and history of the planet's physical material, the processes by which it is formed, moved, and changed, the history of life on Earth, and human interactions with the, geographical Geography is the study of the Earth and its lands, features, inhabitants, and phenomena. A literal translation would be "to describe or write about the Earth". The first person to use the word "geography" was Eratosthenes (276-194 B.C.). Four historical traditions in geographical research are the spatial analysis of natural and, and oceanographic Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean. It covers a wide range of topics, including marine organisms and ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and the geology of the sea floor; and fluxes of various chemical substances and texts refer to tsunamis as "seismic sea waves."
Some meteorological Meteorology is the interdisciplinary scientific study of the atmosphere that focuses on weather processes and short term forecasting . Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the eighteenth century. The nineteenth century saw breakthroughs occur after observing networks developed conditions, such as deep depressions A low pressure area, or "low", is a region where the atmospheric pressure at sea level is lower in relation to surrounding locations. Low pressure systems form under areas of wind divergence which occur in upper levels of the troposphere. Within the field of atmospheric dynamics, these areas of wind divergence aloft are either on the that cause tropical cyclones A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones feed on heat released when moist air rises, resulting in condensation of water vapor contained in the moist air. They are fueled by a different heat mechanism than other cyclonic, can generate a storm surge Storm surge is an offshore rise of water associated with a low pressure weather system, typically a tropical cyclone. Storm surge is caused primarily by high winds pushing on the ocean's surface. The wind causes the water to pile up higher than the ordinary sea level. Low pressure at the center of a weather system also has a small secondary effect,, called a meteotsunami A meteotsunami or meteorological tsunami is a tsunami-like wave phenomenon of meteorological origin. Tsunamis and meteotsunamis propagate in the water in the same way and have the same coastal dynamics. In other words, for an observer on the coast where it strikes the two types would look the same. The difference is in their source only. One, which can raise tides Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth. Most places in the ocean usually experience two high tides and two low tides each day , but some locations experience only one high and one low tide each day (diurnal tide). The times several metres above normal levels. The displacement comes from low atmospheric pressure Atmospheric pressure is the force per unit area exerted against a surface by the weight of air above that surface in the Earth's atmosphere. In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. Low pressure areas have less atmospheric mass above within the centre of the depression. As these storm surges Storm surge is an offshore rise of water associated with a low pressure weather system, typically a tropical cyclone. Storm surge is caused primarily by high winds pushing on the ocean's surface. The wind causes the water to pile up higher than the ordinary sea level. Low pressure at the center of a weather system also has a small secondary effect, reach shore, they may resemble (though are not) tsunamis, inundating vast areas of land. Such a storm surge inundated Burma Burma, officially the Union of Myanmar, is the largest country by geographical area in mainland Southeast Asia. The country is bordered by People's Republic of China on the north-east, Laos on the east, Thailand on the south-east, Bangladesh on the west, India on the north-west and the Bay of Bengal to the south-west with the Andaman Sea defining in May 2008.
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Etymology
The term tsunami comes from the Japanese, meaning "harbor A harbor or harbour , or haven, is a place where ships, boats, and barges can seek shelter from stormy weather, or else are stored for future use. Harbors can be natural or artificial. An artificial harbor has deliberately-constructed breakwaters, sea walls, or jettys, or otherwise, they could have been constructed by dredging, and these require" (tsu, 津) and "wave In fluid dynamics, wind waves or, more precisely, wind-generated waves are surface waves that occur on the free surface of oceans, seas, lakes, rivers, and canals or even on small puddles and ponds. They usually result from the wind blowing over a vast enough stretch of fluid surface. Some waves in the oceans can travel thousands of miles before" (nami, 波). (For the plural, one can either follow ordinary English practice and add an s, or use an invariable plural as in the Japanese.[6])
Tsunami are sometimes referred to as tidal waves. In recent years, this term has fallen out of favor, especially in the scientific community, because tsunami actually have nothing to do with tides. The once-popular term derives from their most common appearance, which is that of an extraordinarily high tidal bore A tidal bore is a tidal phenomenon in which the leading edge of the incoming tide forms a wave (or waves) of water that travel up a river or narrow bay against the direction of the current. As such, it is a true tidal wave (not to be confused with a tsunami). Tsunami and tides both produce waves of water that move inland, but in the case of tsunami the inland movement of water is much greater and lasts for a longer period, giving the impression of an incredibly high tide. Although the meanings of "tidal" include "resembling"[7] or "having the form or character of"[8] the tides, and the term tsunami is no more accurate because tsunami are not limited to harbours, use of the term tidal wave is discouraged by geologists A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes and history that has shaped it. Geologists usually engage in studying geology. Geologists, studying more of an applied science than a theoretical one, must approach Geology using physics, chemistry and biology as well as other and oceanographers Oceanography , also called oceanology or marine science, is the branch of Earth science that studies the ocean. It covers a wide range of topics, including marine organisms and ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and the geology of the sea floor; and fluxes of various chemical substances and.
There are only a few other languages that have a native word for this disastrous wave. In the Tamil language Tamil (தமிழ் tamiḻ; [t̪ɐmɨɻ] ) is a Dravidian language spoken predominantly by Tamil people of the Indian subcontinent. It has official status in the Indian state of Tamil Nadu and in the Indian union territory of Puducherry. Tamil is also an official language of Sri Lanka and Singapore. It is one of the twenty-two scheduled, the word is aazhi peralai. In the Acehnese language Acehnese or Aceh (formerly Atjeh) is a Malayo-Polynesian language spoken in Aceh, Sumatra, Indonesia and Bota, Perak, Malaysia, it is ië beuna or alôn buluëk [9] (Depending on the dialect. Note that in the fellow Austronesian The branches of the Oceanic languages: Admiralties and Yapese St Matthias Western Oceanic & Meso-Melanesian Temotu Southeast Solomons Southern Oceanic Micronesian Fijian-Polynesian The black ovals at the northwestern limit of Micronesian are the Sunda-Sulawesi languages Palauan and Chamorro. The black circles in with the green are offshore language of Tagalog Tagalog is an Austronesian language spoken in the Philippines by about 22 million people. It is related to Austronesian languages such as Indonesian, Malay, Javanese and Paiwan (of Taiwan), Cham (of Vietnam and Cambodia), and Tetum (of East Timor). It is the first language of the Philippines' Region IV (CALABARZON and MIMAROPA), first language of, a major language in the Philippines The Philippines , officially known as the Republic of the Philippines (Filipino: Republika ng Pilipinas), is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam. The Sulu Sea to the southwest lies between the country and the island of Borneo, and, alon means "wave".) On Simeulue island, off the western coast of Sumatra in Indonesia, in the Defayan language The Simeulue language is spoken on Simeulue island, off the western coast of Sumatra in Indonesia the word is smong, while in the Sigulai language it is emong.[10]
Generation mechanisms
The principal generation mechanism (or cause) of a tsunami is the displacement of a substantial volume of water or perturbation of the sea.[11] This displacement of water is usually attributed to either earthquakes, landslides, volcanic eruptions, or more rarely by meteorites and nuclear tests.[12][13] The waves formed in this way are then sustained by gravity. It is important to note that tides Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth. Most places in the ocean usually experience two high tides and two low tides each day , but some locations experience only one high and one low tide each day (diurnal tide). The times do not play any part in the generation of tsunamis, hence referring to tsunamis as 'tidal waves' is inaccurate.
Seismicity generated tsunamis
Tsunamis can be generated when the sea floor abruptly deforms and vertically displaces the overlying water. Tectonic earthquakes are a particular kind of earthquake that are associated with the earth's crustal deformation; when these earthquakes occur beneath the sea, the water above the deformed area is displaced from its equilibrium position.[14] More specifically, a tsunami can be generated when thrust faults A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. They are often recognized because they place older rocks above younger. Thrust faults are the result of compressional forces associated with convergent In plate tectonics, a convergent boundary also known as a destructive plate boundary , is an actively deforming region where two (or more) tectonic plates or fragments of lithosphere move toward one another and collide. As a result of pressure, friction, and plate material melting in the mantle, earthquakes and volcanoes are common near convergent or destructive plate boundaries Plate tectonics is a scientific theory which describes the large scale motions of Earth's lithosphere. It is vital for the existence of life on earth because of the role that it plays in the global cycle that maintains the balance of carbon between the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere. A similar process likely takes move abruptly, resulting in water displacement, due to the vertical component of movement involved. Movement on normal faults will also cause displacement of the seabed, but the size of the largest of such events is normally too small to give rise to a significant tsunami.
Tsunamis have a small amplitude Amplitude is the magnitude of change in the oscillating variable with each oscillation within an oscillating system. For example, sound waves in air are oscillations in atmospheric pressure and their amplitudes are proportional to the change in pressure during one oscillation. If a variable undergoes regular oscillations, and a graph of the system (wave height) offshore, and a very long wavelength In physics, the wavelength of a sinusoidal wave is the spatial period of the wave – the distance over which the wave's shape repeats. It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a characteristic of both traveling waves and (often hundreds of kilometers long), which is why they generally pass unnoticed at sea, forming only a slight swell usually about 300 millimetres (12 in) above the normal sea surface. They grow in height when they reach shallower water, in a wave shoaling process described below. A tsunami can occur in any tidal state and even at low tide can still inundate coastal areas.
On April 1, 1946, a magnitude-7.8 (Richter Scale The Richter magnitude scale, also known as the local magnitude scale, assigns a single number to quantify the amount of seismic energy released by an earthquake. It is a base-10 logarithmic scale obtained by calculating the logarithm of the combined horizontal amplitude (shaking amplitude) of the largest displacement from zero on a particular type) earthquake An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. Earthquakes are measured with a seismometer; a device which also records is known as a seismograph. The occurred near the Aleutian Islands The Aleutian Islands are a chain of more than 300 small volcanic islands forming part of the Aleutian Arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi (17,666 km²) and extending about 1,200 mi (1,931 km) westward from the Alaska Peninsula toward the Kamchatka Peninsula. Crossing longitude 180°, they are the westernmost part of, Alaska Alaska was purchased from the Russian Empire on March 30, 1867, for $7.2 million at about two cents per acre . The land went through several administrative changes before becoming an organized territory on May 11, 1912, and the 49th state of the U.S. on January 3, 1959. It generated a tsunami which inundated Hilo Hilo is a coastal town in the State of Hawaiʻi. It is the largest settlement on the island of Hawaiʻi, and the second largest settlement in the state. The population was 40,759 at the 2000 census on the island of Hawai'i with a 14 metres (46 ft) high surge. The area where the earthquake An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time. Earthquakes are measured with a seismometer; a device which also records is known as a seismograph. The occurred is where the Pacific Ocean floor is subducting (or being pushed downwards) under Alaska.
Examples of tsunami at locations away from convergent boundaries include Storegga about 8,000 years ago, Grand Banks 1929, Papua New Guinea 1998 (Tappin, 2001). The Grand Banks and Papua New Guinea tsunamis came from earthquakes which destabilized sediments, causing them to flow into the ocean and generate a tsunami. They dissipated before traveling transoceanic distances.
The cause of the Storegga sediment failure is unknown. Possibilities include an overloading of the sediments, an earthquake or a release of gas hydrates (methane etc.)
The 1960 Valdivia earthquake (Mw 9.5) (19:11 hrs UTC), 1964 Alaska earthquake (Mw 9.2), and 2004 Indian Ocean earthquake (Mw 9.2) (00:58:53 UTC) are recent examples of powerful megathrust earthquakes that generated tsunamis (known as teletsunamis) that can cross entire oceans. Smaller (Mw 4.2) earthquakes in Japan can trigger tsunamis (called local and regional tsunamis) that can only devastate nearby coasts, but can do so in only a few minutes.
In the 1950s, it was discovered that larger tsunamis than had previously been believed possible could be caused by giant landslides. This phenomena rapidly displace large water volumes, as energy from falling debris or expansion transfers to the water at a rate faster than the water can absorb. Their existence was confirmed in 1958, when a giant landslide in Lituya Bay, Alaska, caused the highest wave ever recorded, which had a height of 524 metres (over 1700 feet). The wave didn't travel far, as it struck land almost immediately, killing 2 people fishing in the bay, whilst the other boat amazingly managed to ride the wave. Scientists named these waves megatsunami.
Scientists discovered that extremely large landslides from volcanic island colapses can generate megatsunami, that can travel trans-oceanic distances.
Characteristics
When the wave enters shallow water, it slows down and its amplitude (height) increases. The wave further slows and amplifies as it hits land. Only the largest waves crest.While everyday wind waves have a wavelength (from crest to crest) of about 100 metres (330 ft) and a height of roughly 2 metres (6.6 ft), a tsunami in the deep ocean has a wavelength of about 200 kilometres (120 mi). Such a wave travels at well over 800 kilometres per hour (500 mph), but due to the enormous wavelength the wave oscillation at any given point takes 20 or 30 minutes to complete a cycle and has an amplitude of only about 1 metre (3.3 ft).[15] This makes tsunamis difficult to detect over deep water. Ships rarely notice their passage.
As the tsunami approaches the coast and the waters become shallow, wave shoaling compresses the wave and its velocity slows below 80 kilometres per hour (50 mph). Its wavelength diminishes to less than 20 kilometres (12 mi) and its amplitude grows enormously, producing a distinctly visible wave. Since the wave still has such a long wavelength, the tsunami may take minutes to reach full height. Except for the very largest tsunamis, the approaching wave does not break (like a surf break), but rather appears like a fast moving tidal bore.[16] Open bays and coastlines adjacent to very deep water may shape the tsunami further into a step-like wave with a steep-breaking front.
When the tsunami's wave peak reaches the shore, the resulting temporary rise in sea level is termed 'run up'. Run up is measured in metres above a reference sea level.[16] A large tsunami may feature multiple waves arriving over a period of hours, with significant time between the wave crests. The first wave to reach the shore may not have the highest run up.[17]
About 80% of tsunamis occur in the Pacific Ocean, but are possible wherever there are large bodies of water, including lakes. They are caused by earthquakes, landslides, volcanic explosions, and bolides.
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Wed, 04 Aug 2010 15:52:17 GMT+00:00
ColdBee (blog) ... our satellite solar flares sun's 'solar tsunami ' august 2010 solar flares, coronal mass ejections and Aurora Borealis or the Northern Lights tonight. ...
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Publicidade O Tsunami de 2004 matou mil vezes mais do que os Atentados de 11 de Setembro O planeta e mais poderoso do que voce imagina Respeite o Nao acho que a melhor forma de divulgar uma ONG
TMH
Fri, 27 Aug 2010 23:37:06 GM
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Q. Tsunami is a tidal wave and can be figuratively used to refer to any upsurge or raising. Not for a fall. The financial market collapse in US cannot be referred to as "financial tsunami". Will english language experts clarify.Answers with illustrations welcome.
Asked by krish - Wed Oct 8 06:08:07 2008 - - 5 Answers - 0 Comments
A. Figurative language may be correct, as long as the author maintains a clear metaphor. In the case of the term "tsunami," a native English speaker would not think primarily of an "upsurge" of water, but of a cataclysmic event. The English term is "tidal wave," although technically such waves are not "tidal." Also, note that "tsunami" is originally from the Japanese. A tsunami is not merely an upswelling, but a whole series of waves created by the rapid displacement of a large body of water--for instance, by an earthquake on the ocean floor. The high point of such a wave is the "crest," the low point is the "trough." Since such events tend to be cataclysmic, resulting in sudden, widespread damage, an English speaker would most likely… [cont.]
Answered by rangergordon - Wed Oct 8 06:34:20 2008
