Tsunamis eventually visit every coastline in the Pacific Ocean. The most recent tsunami to hit southern California occurred on March 11, 2011. Here are some facts and safety tips about tsunamis you should know when visiting the California coast, including the Channel Islands.
Tsunamis are a series of waves commonly caused by an earthquake beneath the sea floor. They can last for many hours and the first wave is often not the largest.
If you are on a beach or in a harbor and feel an earthquake, no matter how small, immediately move inland or to high ground.
Beaches, harbors, lagoons, bays, estuaries, tidal flats and river mouths are the most dangerous places to be in a tsunami.
You may not receive a warning for a locally-generated tsunami. In addition to earthquake shaking, natural indicators of an approaching tsunami include, a lowering of ocean water that exposes the sea floor, or a rapid surge of water and debris much like a flood.