Tsunamis are series of waves triggered by an earthquake, volcanic activity, or under­water landslide offshore. A tsunami can move at hundreds of miles per hour and can be 10–100 feet high. Even 10-foot tsunamis can be very destructive. Areas near the coast, within a mile of the shoreline, and that are less than 25 feet above sea level are at the most risk for a tsunami.



Prep Steps

  • Verify and update official contact information in the Marine Corps Enterprise Mass Notification System (eMNS), and register all cell phones, home phone, email addresses, etc. in eMNS. 

  • Determine whether you live or work in an area with the potential to be hit by a tsunami.

  • Locate tsunami signs.

  • Make a written evacuation plan as a family. You should identify a place to evacuate that is at least 100 feet above sea level or two miles inland. You should be able to reach it within 15 minutes.

  • Whether you live in the area or are a tourist, know the community’s warning systems and evacuation protocols.

  • Make a written communication plan in case family members are separated.

  • Build an emergency kit.



Tsunami Terminology

  • Warning—A tsunami with the potential to generate widespread inundation is imminent or expected. People in the warned area are encouraged and may be ordered to evacuate.

  • Advisory—A tsunami with the potential to generate strong currents or waves dangerous to those in or very near the water may be imminent or expected, but significant inundation is not expected for areas under an advisory. Beaches, harbors, and marinas in the warned area may be closed.

  • Watch—An earthquake that could produce a tsunami has been detected.

  • Information Statement—In most cases indicates that an earthquake has occurred or a warning, watch, or advisory has been issued for another section of the ocean with no imminent threat to the local area to prevent unnecessary evacuations.



What to do after a Tsunami

  • Continue to listen to news reports and stay tuned to eMNS alerts for further information and instructions.

  • Stay clear of flood waters (standing and moving) as they may be contaminated or deeper than expected.

  • Stay clear of damaged areas until you are told otherwise.

  • Beware of downed power lines.

  • Return home only after local officials tell you it is safe.

  • Avoid any roads where waters have receded as they may have weakened and could collapse under the weight of a car.

  • Be extremely cautious when entering buildings and homes as there may be unseen damage.

  • Clean and disinfect everything that was touched by flood water, as it can contain sewage and other contaminants.


Set your own course through any hazard: stay informed, make a plan, build a kit. Live Ready Marine Corps.