The planet Earth is subject to dynamic processes that cause continual transformation. The most visible changes occur in the Earth’s crust, which is fragmented into tectonic plates. The Caribbean Sea, the Greater Antilles (except for most of Cuba) and the Lesser Antilles lie on the Caribbean tectonic plate. This plate also covers the continental area of most of Central America and part of the Pacific Ocean closest to the coast of Central America. This plate has a total surface area of 3.2 million square kilometers.

The geology and land structures on the Caribbean plate are the result of geologic processes that have occurred since its formation. We can reconstruct the evolution of the Caribbean plate since its origin by studying its current geology and a complex interpretation of the sequence of geologic events. The oldest rocks documented in the Caribbean plate are of oceanic origin and date to the Jurassic period.

The Caribbean plate is constantly interacting with the tectonic plates that surround it:

  • The contact with the North America plate to the north is a transform fault. In this area, the movement is side by side, as the North America plate moves to the west in relation to the Caribbean plate. The main result is seismic activity, produced by the friction between the rocks. A recent example is the earthquake in Haiti.
  • The contact with the North America and South America plates to the east is a subduction zone. Seismic activity and volcanic activity are generated along this border as oceanic material is subducted under the Caribbean plate. The clearest evidence of this is found in the Lesser Antilles, where there are 17 active volcanoes, including on the islands of Montserrat, Martinique, Guadeloupe, St. Vincent and Grenada.
  • The contact with the South America plate to the south, which moves to the west in relation to the Caribbean plate, creates a transform fault zone. The complexity of this border causes seismic activity and includes a subduction zone, due to the variations in the contact between the plates.
  • The contact with the Cocos plate to the west is a subduction zone, due to the fact that the Pacific plate is denser than the border of the continental material of Central America. The result is the volcanic arc in Central America, with volcanoes in Guatemala, El Salvador, Nicaragua and Costa Rica.
  • The contact with the Nazca plate, directly to the west of the Panama block, is another transform fault boundary.

The wealth of geological structures that result from these movements of tectonic plates is studied in each of the countries that are part of the Caribbean plate. One important motive for these studies is the search for mineral resources that contribute to the economies of many of these countries. Another crucial aspect is the study of geological risks, due to the many lives lost to volcanic eruptions, earthquakes and tsunamis. Zones such as the Puerto Rico trench, the deepest spot in the Atlantic Ocean, are susceptible to earthquakes that can cause tsunamis.

Author: Ruth Vélez
Published: December 20, 2011.

Related Entries

This post is also available in: Español


The Puerto Rico Endowment for the Humanities welcomes the constructive comments that the readers of the Encyclopedia of Puerto Rico want to make us. Of course, these comments are entirely the responsibility of their respective authors.