Tsunami Hazard Mapping

   Tsunamis, also known as tidal waves, are rapidly moving waves or temporary rises in sea level caused by the sudden displacement of a large body of water. Most commonly caused by underwater landslides as result of an earthquake, tsunamis can also be caused by underwater or near-water volcanic eruptions, explosions, or landslides either into or below the water surface. Tsunamis can cause death, injury, or property damage as the resultant wave run-up inundates or floods coastal areas.  

   Mapping of coastal areas subject to tsunami hazard helps prevent losses, plan evacuation routes, and prepare for emergencies. In addition, a network of tsunami monitoring buoys can help detect an oncoming tsunami, and multiple regional tsunami warning centers can issue alerts.

   In the United States, coastal areas of the the Pacific Rim - Alaska, Hawaii, California, Oregon, and Washington are more likely to be subjected to tsunamis although a tsunami could potentially occur in any low-lying coastal area. Local areas may have tsunami evacuation maps in the local phonebook. NOAA/NWS issues tsunami warnings and allerts and provides funding and assistance with multiple tsunami warning centers. FEMA, and other federal, state, or local agencies may be involved as well. Some resources are listed at left.

   To learn more about tsunami hazards in your area, contact the appropriate local, state or federal agency. If you plan to build, develop, or inhabit areas subject to tsunami hazards, consult a qualified professional regarding the hazard, your risk, and options for mitigation. The information on this site is only intended as an educational tool to help you get started. By using it you are subject to our terms of use.

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Tsunami hitting the coast, Hawaii, 1957.

Photo H.Helbush, Courtesy NOAA