Tsunami

Preparing for a Tsunami

Tsunamis are a series of large ocean waves generated by major earthquakes beneath the ocean floor or major landslides into the ocean. Tsunamis are most often generated by earthquake-induced movement of the ocean floor. Landslides, volcanic eruptions, and even meteors can also generate a tsunami.

Since 1946, tsunamis have been the cause of 350 deaths and a half-billion dollars in property damage in Hawaii, Alaska, and the U.S. West Coast. If a major earthquake is felt, a tsunami could reach the beach in a few minutes, even before a warning is issued. Areas at greatest risk are less than 25 feet above sea level and within one mile of the shoreline. If you are in a tsunami risk area, learn how to protect yourself, your family, and your property.

 

Prepare for Tsunamis

  • Know the height of your street above sea level and the distance of your street from the coast or other high risk waters. Evacuation orders may be based on these numbers.
  • Plan evacuation routes from your home, school, workplace and other places you could be where tsunamis present a risk. If possible, pick areas 100 feet (30 meters) above sea level or go as far as two miles inland, away from the coastline. If you cannot get this high or far, go as high or far as you can. Every foot inland or upward may make a difference. You should be able to reach your safe location on foot within 15 minutes.
  • Find out what the school evacuation plan is. Find out if the plan requires you to pick your children up from school or from another location. Telephone lines during a tsunami watch or warning may be overloaded and routes to and from schools may be jammed.
  • Practice your evacuation routes. Familiarity may save your life. Be able to follow your escape route at night and during inclement weather. Practicing your plan makes the appropriate response more of a reaction, requiring less thinking during an actual emergency.
  • If you are a tourist, familiarize yourself with local tsunami evacuation protocols.  You may be able to evacuate safely to the third floor and higher in reinforced concrete hotel structures.

 

Know the Difference

  • Tsunami Warning: A tsunami was or may have been generated, which could cause damage; therefore, people in the warned area are strongly advised to evacuate.
  • Tsunami Watch: A tsunami was or may have been generated, but is at least two-hours, travel time to the area in watch status. Local officials should prepare for possible evacuation if their area is upgraded to a warning.
  • Tsunami Advisory: An earthquake has occurred in the Pacific basin, which might generate a tsunami. WC/ATWC and PTWC will issue hourly bulletins updating the situation.
  • Tsunami Information: A message with information about an earthquake that is not expected to generate a tsunami. Usually only one bulletin is issued.

 

What to do During a Tsunami Watch

  • Use a NOAA Weather Radio or tune to a Coast Guard emergency frequency station or a local radio or television station for updated emergency information.
  • Locate household members and review evacuation plans. Be ready to move quickly if a tsunami warning is issued.

 

What to do During a Tsunami Warning

  • If you hear an official tsunami warning or detect signs of a tsunami, evacuate at once.
  • Take your emergency preparedness kit. Having supplies will make you more comfortable during the evacuation.
  • Take your pets with you. If it is not safe for you, it’s not safe for them.
  • Get to higher ground as far inland as possible. Watching a tsunami could put you in grave danger. If you can see the wave, you are too close to escape it.
  • Continue using a NOAA Weather Radio or tuning to a Coast Guard station or a local radio or television station for the latest updates.
  • Return home only after local officials tell you it is safe. A tsunami is a series of waves that may continue for hours. Do not assume that after one wave the danger is over. The next wave may be larger than the first one.
  • Check yourself for injuries and get first aid as needed, before helping injured or trapped persons. If someone needs to be rescued, call professionals with the right equipment to help. Many people have been killed or injured trying to rescue others.
  • Help people who require special assistance—infants, elderly people, those without transportation, people with disabilities and large families who may need additional help in an emergency situation.
  • Avoid disaster areas. Your presence might interfere with emergency response operations and put you at further risk from the residual effects of floods.
  • Use the telephone only for emergency calls.
  • Stay out of any building that has water around it. Tsunami water can cause floors to crack or walls to collapse.
  • Use caution when re­entering buildings or homes. Tsunami­driven flood water may have damaged buildings where you least expect it. Carefully watch every step you take.
  • To avoid injury, wear protective clothing and be cautious when cleaning up.
  • Watch animals closely and keep them under your direct control.