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Tsunamis, also known as seismic sea waves, are most common along the Pacific coast, but can strike anywhere along the U.S. coastline. Tsunamis are enormous waves caused by an underground disturbance such as an earthquake. They can move hundreds of miles per hour, and hit land with waves topping 100 feet in height.

Understanding the difference between the terms that identify a tsunami hazard: advisory, watch and warning. For a detailed explanation of these terms, see


Plan to act quickly.

If you are in coastal waters and notice a dramatic recession of water from the shoreline you should heed nature's warning that a tsunami is approaching.

Move inland immediately and do not return to the flooded and damaged areas until officials say it is safe to do so.

Visit NOAA Weather-Ready Nation for more weather-related information.

Stay informed

Learn about the emergency plans that have been established in your area by your state and local government. In any emergency, always listen to the instructions given by local emergency management officials.

Jefferson County Department of Emergency Management (DEM) offers Nixle alerts. These are text messages (on your cell phone or via email) with important public safety information that can include road closures, severe weather advisories, and other public safety information.

  • Navigate to at

  • Follow the simple steps to sign up. When you receive a text message from 888777, reply to complete the sign-up process.

  • This is a free service from Jefferson County Emergency Management however if you chose text alerts and have a phone plan that charges for text messages, normal text message fees by your phone service charges may apply.

In the event of a major power outage, officials recommend getting information by listening to your car radio.

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