As there are tsunami

As there are tsunami

Tsunami are huge oceanic waves which are formed because of powerful impact of natural cataclysms on all thickness of water. On coast of the Pacific Ocean more than 80% of cases of emergence of a tsunami are observed.


1. Underground earthquakes are the main reason for emergence of a tsunami. More than 85% of cases of emergence of these huge waves fall to their share. At an earthquake at an ocean floor there is a vertical motion of soil. A part of a bottom rises, and another – falls. The surface of the ocean begins to fluctuate down, seeking to return to a starting position, as generates a series of long waves.

2. Not each underwater earthquake leads to formation of a tsunami. Only rather strong earthquake with the center located superficially under a bottom can carry out a motion of all layer of water. Besides, underwater pushes have to enter a resonance with fluctuations of waves.

3. About 7% of a tsunami are a consequence of landslides. Often the earthquake leads to a landslide, and already it generates a powerful wave. Because of an earthquake on Alaska in 1958 in the bay Lutuya there was a landslide. The huge mass of ice and rocks collapsed from height of 1100 m in water. There was a wave which reached height more than 520 m on the opposite coast of the bay.

4. About 5% of tsunami formation are the share of underwater volcanic eruptions. Large volcanic explosions cause the shock wave shaking water weight. Besides, water starts moving, seeking to fill emptiness from the cast-out material. Huge tsunami were generated by a volcanic eruption of Krakatau in 1883.

5. Human activity can become the reason of emergence of a tsunami also. In 1948 as a result of the underwater atomic explosion made by the USA there was a wave 28.6 m high.

6. Falling of a large meteorite to the ocean can also cause destructive waves.

7. Waves up to 21 m high can be formed because of wind of storm force. However they are not a tsunami as in this case there is no motion of all thickness of a water layer. Besides, storm waves are short and cannot cause considerable floodings ashore.

Author: «MirrorInfo» Dream Team