Tsunamis

About Tsunamis

A tsunami is a series of long ocean waves caused by an underwater disturbance such as an earthquake, landslide, volcanic eruption or meteorite. They are a danger to anyone near an ocean.

A tsunami can move hundreds of miles per hour and crash into land with waves of 100 feet or higher. Most tsunami-related deaths are caused by drowning.

If you are in a coastal area, you should know

  • Highest risk areas are less than 25 feet above sea level and within one mile of shoreline.
  • The first tsunami wave may NOT be the largest or most severe. Tsunami danger can last for several hours after arrival of the first wave.
  • Tsunamis can occur at any time of day or night, during any season.
  • Tsunami warning signs include:
    • a strong earthquake lasting 20 seconds or longer near the coast
    • a rapid rise or fall in coastal waters

If you are in a tsunami risk area

  • Know the height of your street above sea level and the distance of your street from the coast and other high-risk waters. Contact your local emergency management office or American Red Cross chapter to determine if you are in a tsunami hazard area.
  • Have an engineer check your home and advise on methods to make it more resistant to tsunami.
  • Prepare a Family Disaster Plan to include: a Family Communications Plan and an Emergency Disaster Kit. This should include food and water for three days, bedding, tent/camping supplies, medicine, cash, credit cards, flashlights and sturdy shoes.
  • Plan and practice evacuation routes from home, school or work. Select an area higher than 100 feet above sea level or up to two miles inland, away from the coastline and within a 15-minute walk.
  • Follow posted evacuation routes to shelters. Be aware: footpaths often lead uphill and inland; while roads often parallel coastlines.

If a tsunami occurs

  • Follow local emergency and law enforcement evacuation advice. Listen to a NOAA (National Oceanic & Atmospheric Administration) Weather Radio with a tone alert for local watches and warnings.
  • If trapped and unable to reach higher ground, go to an upper story of a sturdy building or get on the roof.
  • Remain at a higher elevation until the tsunami threat has completely passed. Additional severe weather activity is likely to follow initial quakes and early waves. Local officials will alert an "all clear" advisory when appropriate.
  • Bring outdoor lawn furniture, garden equipment, bicycles, toys and decorations indoors.
  • Park, lock and leave vehicles at a higher elevation.

After a Tsunami

  • Stay tuned to NOAA Weather Radio for emergency updates.
  • Avoid collapsed or deteriorated bridges and roads.
  • Avoid downed power lines.
  • Obtain first-aid for injured persons as needed.
  • Restrict telephone use to emergency calls.

When attempting to re-enter buildings, damage or dangers may not be immediately visible. Use extreme caution or seek professional help as live wires, electrical shorts, gas leaks, sewage or water line damage or dangers may be present.

Check food and water supplies. Use your emergency water or boil tap water before drinking until you are told the water supply is safe. Food that came in contact with flood waters may be contaminated and should be discarded.