The Virgin Islands are located close to several fault lines, which is why we have frequent small earthquakes. These small earthquakes are generally characterized by mild shaking. Tectonic activity may even sound like rumbling thunder on a cloudless day. It is important to seek safety in a doorway or beneath a sturdy table no matter how strong the earthquake is. But what do you do if the earthquake is strong enough to generate a tsunami?
If there is an incoming tsunami, most likely you will hear sirens. St. John is equipped with seven tsunami sirens that are located in Cruz Bay, Coral Bay, Francis Bay, Roman Hill Road, Hansen Bay, Frank Bay, and Calabash Boom. However, if you are at the beach and you feel or hear an earthquake, or you begin to notice that the water is receding, don’t wait to hear the sirens go off; evacuate to higher ground immediately. Alert those around you who may be unaware of tsunami safety protocols. Always prioritize your life over your possessions. Leave your things behind to make it easier to flee. Luckily, St. John’s topography is mountainous, so making it to higher ground should only take a matter of minutes or seconds (for those who are able bodied). If you are confident enough in your own safety, help those around you who might have a hard time making it uphill.
These are the seven tsunami siren locations on St. John.
In the event of an earthquake that is significant in strength, you will receive a territory-wide alert from VITEMA. A warning suggests that a tsunami could potentially form. In this case it is critical that you evacuate to higher ground or to the nearest tall, sturdy building. An advisory means that a tsunami is not anticipated, but wave currents are likely to be strong. In other words, avoid the beaches. A watch is issued when an earthquake has occurred, but its potential impacts are uncertain. When VITEMA issues a watch, they will send out an update shortly after to inform people on what safety measures should be taken. Lastly, an information statement will be sent out when there is no real threat of a tsunami, but the magnitude of the earthquake suggests that there may be strong currents.
Photo courtesy of the St. John Historical Society
The question is not if but when a tsunami will hit the Virgin Islands. The last tsunami occurred in 1867 after a 7.5 magnitude earthquake. It was reported that the tsunami hit Charlotte Amalie approximately 10 minutes after the earthquake. Shortly after, a second earthquake hit, followed by another tsunami, once again, 10 minutes later. Wave heights were reported to be around 15 to 20 feet tall, and flooding persisted 250 feet inland.
In the past, people had 10 minutes to get out of harm's way. With this in mind, always plan out an evacuation route when you are at the beach or any other lowland areas. This simple planning could save your life. Following a severe earthquake or a tsunami, listen to the radio, find information on the internet about the catastrophe, or call VITEMA at (340-776-2244) for further instruction on the next steps of recovery.