Tsunami

The term "tsunami" of Japanese origin in a literal translation sounds like "wave in the bay." Previously, people called him - the waves ebb and flow, but recently the term is not used in the original sense, because nothing to do with tides tsunami have.

Consists of a tsunami is not a single wave, as many believe, but a number of surface waves that follow one after the other. During the first wave of a powerful tsunami is not always the most destructive, usually waves approach the shore a few hours.

Cause usually are: earthquakes and underwater tremors. The occurrence of the earthquake is usually possible if the underwater shaking the earth's crust is strong enough and can make a huge mass of water to move.

Most tsunami (which is approximately 80%) occur in the Pacific Ocean.

In the 4th century. BC Greek historian whose name Thucydides, in his book "The History of the Peloponnesian War" was first put forward the hypothesis that the concussion of the seabed is the cause of the tsunami.

Tsunamis can cause also fall meteorites, volcanoes, underwater nuclear explosions and even avalanches deep in the mountains. Weather conditions and tropical cyclones can also cause tsunamis.

In the open ocean wave height is often not more than 1 m, while the distance between the ridges 2 can be up to 190 km. The speed of tsunami waves exceeds 800 km / h, which is equal to the speed of a jet plane.

Reaching shallow water, tsunami waves are compressed, their length decreases and height increases. Wave velocity is reduced to approximately 80 km / h.

Tsunami practically impossible to predict. Exceptions are cases allows us to give a warning about the disaster only a few minutes. It is not very common. In such cases, the water near the shore suddenly coming off, indicating that the "sole" of the wave reached the land before the crest.

In 2004, thanks to a decade girl Tilly Smith, during the Indian Ocean tsunami was saved nearly a hundred lives. With a geography lesson Tilly remembered that during the tsunami water can instantly move away from the shore. The girl told about parents who, in turn, had to warn the neighbors on the beach. In honor of the young savior was named an asteroid "20002 Tillismit."