Tsunami
What are tsunamis?
A tsunami is a series of large ocean waves generated by either large, subduction zone earthquakes which deform the ocean floor or by landslides within or falling into the ocean. When the waves enter shallow depths near a coastline, they may rise to several feet or, in rare cases, tens of feet.
If you are on a beach or in low coastal areas it is imperative you are aware that a tsunami could arrive within minutes after a severe earthquake. A tsunami’s danger period can continue for many hours after a major earthquake. Tsunamis can occur during any season of the year and at any time, day or night. 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.
Prepare NOW
- 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.
- Create a family emergency communication plan that has an out-of-state contact. Plan where to meet if you get separated.
- Sign up for your community’s warning system. 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.