Tsunamis: One of the Coast’s Most Destructive Forces

Although March 27 through April 2 is generally recognized as Tsunami Preparedness Week, different states designate different times (though most choose March and April). Those who live on the U.S. East Coast are used to hurricane preparedness, preparing for tsunamis is very different. Some Americans live in higher risk areas for tsunamis, while others may visit one either for pleasure or business.

According to the National Weather Service, a tsunami is one the most powerful and destructive natural forces. It is a series of waves (not just one) caused by a large and sudden disturbance of the sea. Tsunami waves radiate outward in all directions from the disturbance and can move across entire ocean basins. Most tsunamis are caused by undersea earthquakes, but can also be caused by landslides, volcanic activity, certain types of weather and meteorites. Not all earthquakes cause tsunamis.

Luckily, tsunamis are the rarest of Earth’s natural hazards. Each year, a couple of tsunamis cause damage near their source. Although they can strike any U.S. coast, the greatest risk is for states and territories fronting the Pacific or Caribbean. They have no season.

Unlike hurricanes — which we usually can track its path and prepare for in the days before landfall — warnings before tsunamis are often short.

Like hurricanes, there are several levels of warnings:

• Tsunami Warning: Take action — danger! A tsunami that may cause widespread flooding is expected or occurring. Dangerous coastal flooding and powerful currents are possible and may continue for several hours or days after initial arrival. Follow instructions from local officials. Evacuation is recommended. Move to high ground or inland (away from the water).
• Tsunami Advisory: Take action — a tsunami with potential for strong currents or waves dangerous to those in or very near the water is expected or occurring. There may be flooding of beach and harbor areas. Stay out of the water and away from beaches and waterways. Follow instructions from local officials.
• Tsunami Watch: Be aware — a distant earthquake has occurred. A tsunami is possible. Stay tuned for more information. Be prepared to take action if necessary.
• Tsunami Information Statement: Relax — an earthquake has occurred, or a tsunami warning, advisory or watch has been issued for another part of the ocean. Most information statements indicate there is no threat of a destructive tsunami.
  Awareness is important for both residents and visitors. The key take-away is to move to higher ground and stay there. Sometimes the waves may not arrive for hours. Although the likelihood of a tsunami is not high even in areas that are “in the zone,” being aware of your surroundings and following warnings is critical.

For further information, go to http://tsunamizone.org/.