Scientists have found traces of an asteroid-collision event that they say would have created a giant tsunami that swept around the Earth several times, inundating everything except the tallest mountains 3.5 billion years ago. The coastline of the continents was changed drastically and almost all life on land was exterminated.

• Tsunami is a Japanese word. Tsunamis are fairly common in Japan, and many thousands of Japanese have been killed by them in recent centuries.

• An earthquake generates a tsunami if it is of sufficient force and there is violent movement of the earth to cause substantial and sudden displacement of a massive amount of water.

• A tsunami is not a single wave but a series of waves, also known as a wave train. The first wave in a tsunami is not necessarily the most destructive. Tsunamis are not tidal waves.


• Tsunami waves can be very long (as much as 60 miles, or 100 kilometers) and be as far as one hour apart. They are able to cross entire oceans without great loss of energy. The Indian Ocean tsunami traveled as much as 3,000 miles (nearly 5,000 kilometers) to Africa, arriving with sufficient force to kill people and destroy property.

In the open ocean tsunamis can apperar very ery small with a height of less than 3 feet. tsunamis will somtimes go undetected until they approach shallow waters along the coast. These waves have a very large wave lenght up to several hundred miles that is a funtion of the depth of the water where they were formed. Although these waves have a small height, there is a tremendous amount of energy associated with them.As a result of this huge amount of energy these wavescan become gigantic as they approach shallow water.As they crash upon the shore there height depends on the underwater surface features. They can be as heigh as 100 feet or more. In 1737, a huge xave estemated to be 210 feet in height hit Cape Lopatka, Kamchatka Russia.The largest Tsunami ever recorded accored in July of 1958 in Lituya bay, Alaska. A huge rock and icefall sent water surging up to a high water mark of 1640 feet.It's no wounder that these waves can cause such massive destruction and loss of life.