What is Tsunami?

A tsunami is a series of traveling ocean waves of extremely long length generated by
disturbances associated with earthquakes occurring below or near the ocean floor. Underwater volcanic eruptions and landslides can also generate tsunamis. In the deep ocean, their length from wave crest to wave crest may be a hundred miles or more but with a wave height of only a few feet or less. They cannot be felt aboard ships nor can they be seen from the air in the open ocean. In deep water, the waves may reach speeds exceeding 500 miles per hour.

People living near oceans are always being threatened by tsunamis. For example, more than 2000 people were killed when Indonesia was hit by tsunamis in 1992. the great waves caused damages of nearly one billion dollars.