Tsunamis and You: What Jamaicans Should Know

So let’s say a tsunami happens in Jamaica. Would you know what to do? Would you know where to evacuate to, and how? Would you be apprised of what routes would be safe, which ones would not be, what areas would be more vulnerable? These are questions that should cross your mind at some point, especially in a world where natural disasters of magnitudes previously unprecedented have been occurring more frequently. Here’s what Jamaicans should remember about tsunamis:

Tsunamis happen

First of all, according to the Jamaica Tsunami Warning Information Dissemination Protocol and Standard Operating Procedures, “All islands in the Caribbean Sea are vulnerable to tsunamis that may be generated either in the Caribbean or the Atlantic Ocean.” So if you’re thinking that it is an impossibility, think again. In fact, the Caribbean actually has a history of tsunamis. Find out more about Tsunamis in Jamaica’s History and in the Caribbean.

Types of Tsunami Bulletins

Secondly, it is important to understand the different classifications of tsunami bulletins that exist, so that you are clear on the severity of the situation, and the requisite action.

Tsunami Warning: The highest level of tsunami alert. Warnings are issued due to the imminent threat of a tsunami from a large undersea earthquake or following confirmation that a potentially destructive tsunami is underway. They may initially be based only on seismic information as a means of providing the earliest possible alert. Warnings advise that appropriate actions be taken in response to the tsunami threat. Such actions could include the evacuation of low‐lying coastal areas and the movement of boats and ships out of harbors to deep water. Warnings are updated at least hourly or as conditions warrant to continue, expand, restrict, or end the warning.

Tsunami Watch: The second highest level of tsunami alert. Watches are issued based on seismic information without confirmation that a destructive tsunami is underway. It is issued as a means of providing an advance alert to areas that could be impacted by destructive tsunami waves. Watches are updated at least hourly to continue them, expand their coverage, upgrade them to a Warning, or end the alert. A Watch for a particular area may be included in the text of the message that disseminates a Warning for another area.

Tsunami Advisory: The third highest level of tsunami alert. Advisories are issued to coastal populations within areas not currently in either warning or watch status when a tsunami warning has been issued for another region of the same ocean. An Advisory indicates that an area is either outside the current warning and watch regions or that the tsunami poses no danger to that area. The Center(s) issuing the Advisory will continue to monitor the event, issuing updates at least hourly. As conditions warrant, the Advisory will either be continued, upgraded to a watch or warning, or ended.

Tsunami Information Bulletin/Statement: A text product issued to inform that an earthquake has occurred and to advise regarding its potential to generate a tsunami. In most cases, a Tsunami Information Bulletin indicates there is no threat of a destructive
tsunami, and are used to prevent unnecessary evacuations as the earthquake may have been felt in coastal areas. A Tsunami Information Bulletin may, in appropriate situations, caution about the possibility of a destructive local tsunami. A supplemental Tsunami Information Bulletin may be issued if important additional information is received such as a sea level reading showing a tsunami signal. A Tsunami Information Bulletin may also be upgraded to a watch or warning if appropriate.