A tsunami is a series of enormous ocean waves caused by earthquakes, underwater landslides, volcanic eruptions or asteroids. A tsunami can kill or injure people and damage or destroy buildings and infrastructure as waves come in and go out. Tsunamis can:

  • Travel 20-30 miles per hour with waves 10-100 feet high.
  • Cause flooding and disrupt transportation, power, communications and the water supply.
  • Happen anywhere along U.S. coasts. Coasts that border the Pacific Ocean or Caribbean have the greatest risk. New Hanover County beach towns that have south-facing beaches are have a low or very low risk for activity from seismic tsunamis along Caribbean and Puerto Rican fault lines. Even though the risk is low, New Hanover County is a Tsunami Ready community.

Yes and no. A tsunami is a seismic sea wave if it is generated by an earthquake (“seismic” means relating to an earthquake), but tsunamis can also be generated by nonseismic disturbances. Thus, “tsunami” has been internationally adopted to mean waves caused by any large and sudden displacement of the ocean. 

Tsunamis are not related to tides, which result from the gravitational attraction of the Sun and Moon on Earth’s oceans. Therefore, it is incorrect to call a tsunami a tidal wave.

  • Learn the signs of a potential tsunami, such as an earthquake, a loud roar from the ocean, or unusual ocean behavior, such as a sudden rise or wall of water or sudden draining of water showing the ocean floor.
  • Know and practice community evacuation plans. Some at-risk communities have maps with evacuation zones and routes. Map out your routes from home, work and play. Pick shelters 100 feet or more above sea level, or at least one mile inland.
  • Participate in the annual Great Southeast Shakeout held every October
  • Create a family emergency communication plan that has an out-of-state contact. Plan where to meet if you get separated.
  • Sign up to receive emergency alerts. The Emergency Alert System (EAS) and National Oceanic and Atmospheric Administration (NOAA) Weather Radio also provide emergency alerts.
  • Consider earthquake insurance and a flood insurance policy through the National Flood Insurance Program (NFIP). Standard homeowner’s insurance does not cover flood or earthquake damage.

More information on Tsunamis available at Ready.gov in: