Tsunami Preparedness

Tsunamis are giant waves caused by earthquakes or volcanic eruptions under the sea. Out in the depths of the ocean, tsunami waves do not dramatically increase in height, but as the waves travel inland, they build up to higher and higher heights as the depth of the ocean decreases. The speed of tsunami waves depends on ocean depth rather than the distance from the source of the wave. Tsunami waves may travel as fast as jet planes over deep waters, only slowing down when reaching shallow waters. While tsunamis are often referred to as tidal waves, this name is discouraged by oceanographers because tides have little to do with these giant waves.

Updated 2022 Tsunami Hazard Maps

The California Geological Survey released updated Tsunami Hazard Maps in 2022. While Malibu is not at a high risk for a tsunami, beaches and low lying areas are vulnerable. Maximum wave height is forecasted to be eight feet above mean sea level in some areas. For more information and to review the revised maps and expected inundation areas, visit the State of California Conservation webpage or the California Office of Emergency Services My Hazards Map.

How to Find Out If a Tsunami is Approaching

Natural Warning

Strong ground shaking, a loud ocean roar, or the water receding unusually far and exposing the sea floor are all nature’s warnings that a tsunami may be coming. Immediately go to higher ground or inland. A tsunami may arrive within minutes and may last for eight hours or more. Stay away from coastal areas until officials announce that it is safe to return.

Official Warning 

Tsunami Warnings may come via radio, television, telephone, text message, door-to-door contact by emergency responders, or NOAA weather radios. Move away from the beach and seek more information. Follow all directions from emergency personnel, and use your phone only for life-threatening emergencies.

Tsunami Advisory: Take Action - A tsunami with the potential for strong currents or waves dangerous to those in or near the water is expected.

Tsunami Warning: Take Action - Danger! A tsunami that may cause widespread flooding is expected or occurring. 

When Should I Evacuate?

Do Not Wait! Leave as soon as you see any natural signs of a tsunami or receive an official tsunami warning. 

  • GO ON FOOT. Remember what PCH looks like on a Saturday in July - the last place you want to be when a tsunami strikes is trapped in traffic. 
  • Move at least 90 feet above sea level. If this is not possible, move as far inland as you can.
  • If you are outside of a tsunami hazard zone, take no action. You are safer staying where you are.

Prepare Now

Following a tsunami, even those who live outside the tsunami hazard zone could find themselves in a dire situation. PCH is vulnerable to tsunami damage, and many neighborhoods depend on PCH as their only means of egress. In other words, you might live, work, or go to school well out of the reach of even the largest tsunami, but your main transportation route may not be. 

As with any disaster, preparation is the key to survival. You should always keep on hand enough food and water to provide for you, your family, and your pets for at least seven to 10 days following a disaster. Remember, in a wide-scale event, Malibu may not be the first priority for outside help. Each Malibu resident should be prepared to maintain their own livelihoods until help arrives.

For more information, visit The Tsunami Zone California website or download the National Tsunami Hazard Mitigation Program (NTHMP) Tsunami Information Guide offered by the National Weather Service.