In general, if you think a tsunami may be coming, the ground shakes under your feet or you hear there is a warning, tell your relatives and friends, and move quickly to higher ground. If a tsunami occurs, this is what you should do . . . If you are on a boat Important Facts to Know about Tsunamis Tsunamis that strike coastal locations in the Pacific Ocean Basin are most always caused by earthquakes. These earthquakes might occur far away or near where you live.
Some tsunamis can be very large.
All low-lying coastal areas can be struck by tsunamis. A tsunami consists of a series of waves. Often the first wave may not be the largest. The danger from a tsunami can last for several hours after the arrival of the first wave. Tsunamis can move faster than a person can run.