Tsunami (Japanese: tsu = port, nami = wave, which literally means "big waves in the harbor") is the transfer of water bodies caused by changes in sea surface vertically with a sudden. Changes in sea level can be caused by an earthquake centered under the sea, underwater volcanic eruptions, underwater landslides, or or a meteor hit the ocean. Tsunami waves can propagate in all directions. Power contained in the tsunami wave height is fixed to the function and kelajuannya. In the deep ocean, tsunami waves can propagate with the speed of 500-1000 km per hour. Equivalent to the speed of aircraft. Deep-sea wave height is only about 1 meter. Thus, the wave speed is not felt by the ship which was in the middle of the sea. When approaching the coast, the tsunami wave velocity decreases to about 30 km per hour, but its height was increased to reach tens of meters. Tsunami waves can go blow up to tens of kilometers from the beach. Damage and casualties that occur because of the Tsunami can be caused by a blow of water and materials carried by the flow of tsunami waves.
The negative impact caused by tsunamis are destroying everything in its path. Buildings, plants, and resulted in human casualties and causing inundation, salt water contamination of agricultural land, soil, and clean water.
The Greek historian Thucydides was the first name that links the tsunami by an earthquake under the other. But until the 20th century, knowledge about the cause of the tsunami is still very minimal. Research is still underway to understand the causes of tsunamis.
The texts of geology, geography, and oceanography in the past called tsunamis as "seismic sea waves".
Some of the meteorological conditions, such as tropical cyclones, storm surges can cause the so-called meteor tsunami wave height several meters above normal sea. When the storm made landfall, the shape can resemble the tsunami, although not a tsunami. Wave could inundate the land. This storm surge had flooded the Burmese (Myanmar) in May 2008.
The area around the Pacific Ocean has the Pacific Tsunami Warning Centre (PTWC) issued a warning that if there is threat of a tsunami on this region. The area around the Indian Ocean are building Indian Ocean Tsunami Warning System (IOTWS), which will be based in Indonesia.
Historical evidence suggests that megatsunami is possible, which caused some islands to sink
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Terminology____________________________________________
The word tsunami comes from the Japanese tsu means harbor and nami means wave. Tsunamis often Japanese. Japanese history has recorded at least 195 tsunamis occurred.
On several occasions, equated with the tsunami tidal waves. In recent years, this perception has been declared no longer appropriate, particularly within the research community, because the tides have nothing to do with the tsunami. This perception is popular because the first appearance of the tsunami that resembles a high tide.
Tsunamis and tidal waves are equally produces water waves that move to the mainland, but in the tsunami, the wave motion is much larger and longer, so memberika impression as a very high tide. Although the notion that equates with "the tides" includes "resemblance" or "similar character" to surge, this understanding is no longer appropriate. The tsunami not only limited to the harbor. Because of the geological and oceanographically highly not recommend to use the term.
There are only a few local language which has the same meaning with these destructive waves. Aazhi Peralai in Tamil language, ie beuna or Alon buluëk (according to dialect) in the language of Aceh is an example. For the record, in Tagalog version of Austronesian, the main language in the Philippines, Alon means "wave." On Simeulue Island, west coast of Sumatra, Indonesia, in Bahasa Defayan, smong mean a tsunami. While in Language Sigulai, Emong mean a tsunami.
