Whether you live, work, or visit in California, it is important to be aware that the coastal region is vulnerable to tsunamis. Tsunamis can be generated locally or come across the ocean great distances.
California’s large active offshore faults and unstable submarine slopes can cause tsunami activity along the coast. Strong ground shaking from an earthquake is the natural warning that a tsunami might be coming. If you are on the beach or in a harbor and feel an earthquake, immediately move inland or go to high ground. If strong shaking lasts for 20 seconds or more, everyone within the tsunami evacuation area should evacuate as soon as it is safe to do so.
Other natural warnings include seeing the ocean quickly recede to expose the ocean bottom, or hearing an unusually loud roar coming from the ocean. A tsunami can arrive within minutes and may last for several hours.
For tsunamis coming from across the ocean, local communities use a variety of communication methods to broadcast emergency information. Be informed on what signals, sirens, and public services will be employed for your area. Practice tsunami evacuation drills.
Tsunami Preparedness Links
The TsunamiZone is a resource for California as well as regions across the U.S. and worldwide to promote tsunami awareness and preparedness activities, and track participation. Building on the success of Great ShakeOut Earthquake Drills (ShakeOut.org), TsunamiZone.org began in 2014 in California and has expanded as a year-round informational resource allowing individuals and organizations to register their tsunami activities, including public events such as exercises, presentations, and exhibits. Posters, web banners, “Tsunami Walk” guides, and other resources are also provided.
Tsunami Ready The National Weather Service TsunamiReady Program assists communities to become better prepared for tsunamis.
Tsunami Preparedness Brochure for Recreational and Commercial Boaters The California Office of Emergency Services and California Geological Survey have produced a new tsunami preparedness brochure for recreational and commercial boaters.