Tsunamis

Tsunamis are often called tidal waves. This is misleading, because tsunamis are not related to waves. Caused by earthquakes or volcanic activity. It can be hundreds of kilometers in length. It is a chain of fast moving waves caused by fast changes in the ocean. Usually, a tsunami starts suddenly. It will begin as normal waves and change to a very big wave very quickly. The waves travel across an ocean without losing energy. They can remove sand from beaches, destroy trees, damage houses and even wipe out whole towns. If the slope of the coast is shallow, the water may pull back for many hundreds of metres. People who do not know of the danger will often remain at the shore. Tsunamis can not be prevented, but there are ways to help stop people from dying from a tsunami. An earthquake that caused the tsunami can be felt before the wave gets to the shore, people can be warned to go somewhere safe mainly high up land such as mountains.
Drawbacks are a brief warning of a Tsunami; many survivors say that the drawback is followed by a sucking sound. People, who observe drawback, can survive only if they immediately run for high ground.