Tsunamis

A tsunami is a series of large ocean waves created by major earthquakes, underwater volcanic activity or landslides into the ocean.

A tsunami can range in size from just a few feet tall to over 100 feet; it strikes the coast with devastating force and can destroy everything in its path. It may take a tsunami hours or mere minutes to reach shore, so it is important to be well-prepared and know how to respond quickly and effectively.

Before a tsunami

• Check out FLASH Hurricane Strong for simple ways to strengthen your homes against flooding, high winds and lightning.
• Review your family preparedness plan.
• Establish a family communications plan.
• Assemble a disaster supply kit.
• Have a family evacuation plan in place.
• Find out the height of your street above sea level and its distance from the coast.
• Be familiar with tsunami warning signs:
  • Earthquakes, landslides, underwater disturbances or any sizeable ground-shaking.
  • A noticeable recession in water away from the shoreline.
  • Know the difference between a tsunami watch, a tsunami advisory and a tsunami warning:
    • Tsunami warning: A dangerous tsunami is expected or occurring. Take action and move inland to higher ground immediately.
    • Tsunami advisory: A minor tsunami is expected or occurring. Stay out of the water and away from the coast.
    • Tsunami watch: A tsunami is possible. Stay tuned to a National Oceanic and Atmospheric Administration weather radio or TV for more information, and be prepared to take action if necessary.

During a tsunami

• Listen to a NOAA weather radio or TV for the latest information.
• If necessary, follow evacuation orders immediately and move inland to high ground. Head to areas at least 100 feet above sea level and two miles inland. If you can’t get this high or far, go as high and far as possible.
• Remember that a tsunami is a series of waves. Do not assume that one wave means the danger is over. The next wave may be larger than the first one.
• Never go to the beach to watch a tsunami come in. If you can see the wave, you are too close to escape it.

After a tsunami

• Continue listening to a NOAA weather radio or TV for the latest information.
• Be prepared for extensive flooding.
• Avoid damaged areas, stay off roads and remain on firm ground.
• Avoid floodwaters. The water may be contaminated.
• Return home only after local officials declare it is safe. Enter your home with extreme caution. Do not enter if floodwaters remain.
• Inspect your home:
  • Leave the house if you smell gas or chemical fumes.
  • Check for damage to walls, the foundation, the electrical system and water lines.
  • Clean up spilled medicines, bleaches or other flammable liquids immediately.
  • Notify your insurance company if your home is damaged.
• Help injured or trapped people. Do not move seriously injured people unless they are in immediate danger of death or further injury. Call for help.
• Open windows and doors to help dry the house.
• Check food supplies and drinking water. Anything that has come in contact with floodwater may be contaminated and should be thrown out.
• Clean and disinfect everything that got wet.
• Watch out for snakes and other animals. Use a stick to poke through debris.
• Avoid making phone calls except in serious emergencies.

Additional resources

Emergency/preparedness information

• Tsunami preparedness from the American Red Cross
• Federal Emergency Management Agency
  • Ready.gov: Tsunamis
• National Oceanic and Atmospheric Administration
  • Tsunami information 
• National Weather Service
  • Tsunami safety
• U.S. Environmental Protection Agency
  • Natural disaster information

Current tsunami information

• National Weather Service
• National Tsunami Warning Center
• Pacific Tsunami Warning Center

Other information

• NOAA Weather Radio All Hazards