What's Your Tsunami Preparedness?

Millions of people around the world live in areas at risk for tsunamis, such as Hawaii, Alaska, the U.S. and Canadian coasts, Indonesia, Sri Lanka, Thailand, and India. And millions more visit these places every day. Would you know what to do in the event of a tsunami? The following are answers to the most commonly asked questions:

What is a Tsunami?

A tsunami is a series of ocean waves generated by sudden movements in the sea floor, landslides, or volcanic activity. In the deep ocean, the tsunami wave may only be a few inches high. The tsunami wave may come gently ashore or may increase in height as it gets closer to shore to become a fast moving wall of turbulent water several meters high.

Are Tsunamis Common?

Tsunamis are quite rare compared to other hazardous natural events, but they can be just as deadly and destructive. As a result of their rarity, tsunami hazard planning along the U.S. and Canadian west coasts, Alaska and within the Pacific Region is inconsistent. Even in locations with a history of deadly tsunamis, an adequate level of awareness and preparedness is difficult to achieve.

Can a Tsunami be Prevented?

Although a tsunami cannot be prevented, the effect of a tsunami can be reduced through community preparedness, timely warnings, and effective response. NOAA is leading the world in providing tsunami observations and research. Through innovative programs, NOAA is helping coastal communities prepare for possible tsunamis to save lives and protect property.

How Does NOAA’s Tsunami Warning System Work?

DART II Schematic Diagram
DART II Schematic Diagram.

High resolution (Credit: NOAA)

NOAA’s Tsunami Warning System (TWS) monitors the Pacific Basin for potential tsunami activity. As part of the TWS, NOAA operates two Tsunami Warning Centers in Alaska and Hawaii. The Alaska Tsunami Warning Center serves as the regional Tsunami Warning Center for Alaska, British Columbia, Washington, Oregon, and California. The Pacific Tsunami Warning Center serves as the regional Tsunami Warning Center for Hawaii and as a national/international warning center for tsunamis that pose a Pacific-wide threat.

When tsunami activity is detected, NOAA issues tsunami watch, warning, and information bulletins to appropriate emergency officials and the general public by a variety of communication methods. The warning includes predicted tsunami arrival times at selected coastal communities within the geographic area defined by the maximum distance the tsunami could travel in a few hours. If a significant tsunami is detected, the tsunami warning is extended to the entire Pacific Basin.

Because of the December 2004 tsunami in South Asia, NOAA is expanding the U.S. Tsunami Warning Program. This expansion will increase the current Pacific Ocean network of 6 DART Buoys to 39 in the Pacific and Atlantic Oceans and the Caribbean Sea, establish an Atlantic Tsunami Warning Center, deploy second generation buoys, and expand the Tsunami Mitigation Program including outreach and education.

Can the Damage be Minimized?

Yes. For example, the State of Hawaii is addressing tsunami risk through the Hazard Education and Awareness Tool (HEAT), a Web site template that uses Google Maps technology, spatial hazard data, and preparedness information to help increase awareness of coastal hazards.  NOAA’s Pacific Services Center used HEAT to develop a tsunami information service that provides residents and visitors convenient, online access to interactive evacuation zone maps, along with the education and awareness information needed to be prepared in the event of a tsunami.

HEAT project partners in Hawaii include state and local planning and civil defense officials, the Red Cross and other disaster relief agencies.

What Can You Do?

For more information about tsunamis or tsunami preparedness: