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EARTHQUAKES
Eastern Caribbean Earthquakes
The Eastern Caribbean is an example of an island arc system formed at a convergent plate boundary (more
specifically, at a subduction zone, where two tectonic plates meet and the denser plate is forced beneath the
lighter plate). This is the main cause of the volcanic and seismic activity in the Eastern Caribbean.
Most of the earthquakes occurring in the Eastern Caribbean are either tectonic or volcanic in origin. Tectonic
earthquakes are generated when plates move as accumulated energy is released. Volcanic earthquakes are
generated by the movement of magma within the lithosphere. Since magma is less dense than the
surrounding rock, it rises to the surface, breaking the rock as it moves, thereby generating earthquakes. In
fact, more than 75% of the world's earthquakes occur at convergent plate boundaries. The countries of the
Eastern Caribbean are, therefore, highly susceptible to earthquakes.
The most striking example is that
of Trinidad in 1766; although the population was small and the economy minuscule, the effects of the
earthquake were devastating enough to cause the inhabitants to petition the King of Spain to allow
settlement from other, non-Spanish, Caribbean islands. Prior to this event, there was another major
earthquake in Jamaica (N.W Caribbean) in 1692 which resulted in the death of over 2,000 persons and
destroyed 90% of then capital, Port Royal. In fact, it is clear that such major earthquakes are likely to cause
even more damage if they were to occur now or in the future because of growing populations and largescale poorly planned or unauthorized construction.
Although there are considerable variations in the level of activity, no island in the region is completely free
from the threat of earthquakes. Let us now examine the data on the effects that earthquakes have had in
Eastern Caribbean countries over the past 300 years.
Actual earthquake disasters in the Eastern Caribbean over the past 300 years
Source: http://www.uwiseismic.com/General.aspx?id=16