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Tsunami (Japanese: 津 波; 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.
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.
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.

The cause of the tsunami

Tsunamis can occur if an interruption occurs that causes the movement of large amounts of water, such as volcanic eruptions, earthquakes, landslides or meteorite that fell to earth. However, 90% of the tsunami is an earthquake under the sea. In recording the history of some of the tsunami caused by the volcano eruption, for example when the eruption of Mount Krakatoa.
Vertical movement on the earth's crust, can lead to the ocean floor rise or drop suddenly, which resulted in disruption of water balance that is above them. This resulted in the energy flow of sea water, which when it reached the coast into a large wave that caused the tsunami.
The speed of tsunami waves depends on the depth of the sea where the waves occurs, where the speed can reach hundreds of kilometers per hour. When the tsunami reaches the shore, its speed will be around 50 km / h and its energy is very damaging coastal areas in its path. In the midst of the tsunami wave height sea only a few centimeters to several meters, but when it reaches shore wave height can reach tens of meters due to a buildup of the water. When the tsunami reaches the coast of the mainland will crawl away from the coastline with a range of several hundred meters can even be a few kilometers.
This vertical motion can occur on the earth fault or the fault. The earthquake also occurred in the subduction area, where the oceanic plate menelusup down the continental shelf.
The landslide that occurred on the seabed and volcanic debris can also lead to disruption of sea water which can generate a tsunami. The earthquake caused perpendicular movement of the earth layer. As a result, the sea rose and fell abruptly so that the balance of sea water which is above them disturbed. Similarly, cosmic objects or meteor that fell from above. If the size of a meteor or landslide is big enough, can occur megatsunami reach hundreds of meters high.
The quake that caused tsunami
• An earthquake centered in the middle of the sea and shallow (0-30 km)
• An earthquake with a strength of at least 6.5 on the Richter Scale
• An earthquake with a pattern of reverse fault or fault down

Tsunami - Indonesian Wikipedia, the free encyclopedia