A tsunami consists of a series of ocean or sea waves that can be generated by an earthquake, volcanic eruption, landslide or meteoric impact. In deep water, the tsunami can travel as fast as 500 miles per hour (equivalent to the speed of a commercial jet). Near the shore, however, a tsunami slows down, the distance between its waves decreases and the wave height increases, according to a press release from the V.I. Territorial Emergency Management Agency — Emergency Operations Center.
People on beaches or in low coastal areas need to be aware that a tsunami could arrive within minutes of a severe earthquake – and the danger period can continue for many hours. Tsunamis can occur any time of year, day or night. The wave height could be tens of feet, destroying everything along its path when flooding and when receding.
To define the evacuation zone for the U.S. Virgin Islands, an 82-foot (25 meters) elevation profile was used; it was reached within 2 miles of the coast, another factor to consider. This evacuation criterion was based on historical events, tsunami modeling results from Puerto Rico and the US National Tsunami Hazard Mitigation Program guidelines.
See attached Tsunami Evacuation Map for evacuation zones and additional information.
For your Safety Remain Alert To:
- Natural tsunami signs: a very strong or long earthquake and/or abrupt sea level change.
- Tsunami alert messages issued by the UAS National Weather Service Tsunami Warning Centers and the Puerto Rico Seismic Network.
- Evacuation orders issued by the USVI Government through VITEMA.
Be Tsunami Ready
- Have an emergency evacuation kit on hand.
- Study the attached evacuation maps and identify the evacuation zones, evacuation routes, assembly points and high ground.
- Discuss evacuation procedures with children and family members so that in the event of a tsunami, everyone knows what to do.
- Check at your workplace and your children’s schools and day care centers to learn if they are in a tsunami hazard area or inundation zone. Learn about their evacuation plans, especially the designated spot where you will pick up your children.
- Plan evacuation routes from your home, school, workplace and other places you could be where tsunamis present a risk.
- If possible try to pick areas 100 feet above sea level or 2 miles inland. If you cannot get that 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 the highest ground possible on foot within 15 minutes.
- Practice your evacuation routes. Familiarity may save your life. Be able to follow your escape route at night and during inclement weather.
- When a tsunami message is issued, cooperate and follow all instructions from emergency management authorities.
Know the difference
- An Information Statement is issued when an earthquake has occurred and at most there could be minor waves. No action is suggested.
- A Watch is issued when an event has occurred, but the danger level is not yet known. This message will be updated; stay alert for further official information.
- An Advisory is issued when strong currents are likely but no tsunami inundation is expected. Stay away from the shore. This message will be updated; stay alert for further official information.
- A Warning is issued when an inundating wave is possible. A full evacuation is suggested. Get out of the evacuation zone or up a sturdy building as quickly as possible. The message will be updated; stay alert for further official information.
**Note: Once the Tsunami Warning Center believes that the threat of a tsunami has ended, it will issue a cancellation. Nevertheless, if evacuation orders were issued, only return to the evacuated area if the designated authorities have declared it is safe to do so.
Additional Tsunami Preparedness and Response Information