- Puerto Rico Trench
The Puerto Rico Trench is an
oceanic trench located on the boundary between theCaribbean Sea and theAtlantic Ocean . The trench is associated with a complex transition between thesubduction zone to the south along theLesser Antilles island arc and the majortransform fault zone or plate boundary that extends west betweenCuba andHispaniola through theCayman Trench to the coast ofCentral America . Scientific studies have concluded that an earthquake occurring along this fault zone could generate a significanttsunami .cite web| url=http://oceanexplorer.noaa.gov/explorations/03trench/welcome.html| title=Puerto Rico Trench 2003: Cruise Summary Results| author=Uri ten Brink| publisher=National Oceanic and Atmospheric Administration| accessdate=2008-02-21]The island of
Puerto Rico lies immediately to the south of the fault zone and the trench. The trench is 800 kilometers (500 mi) long and has a maximum a depth of 8,605 meters (28,232 ft) atMilwaukee Deep , which is the deepest point in the Atlantic Ocean.Geology
The Puerto Rico Trench is located at a boundary between two plates that pass each other along a transform boundary with only a small component of
subduction . TheCaribbean Plate is moving to the east while theNorth American Plate is moving to the west. The North American Plate is being subducted by the Caribbean Plate to the southeast of the trench. This subduction zone explains the presence of activevolcano es over the southeastern part of the Caribbean Sea. Volcanic activity is frequent along the island arc southeast from Puerto Rico to the coast ofSouth America .Puerto Rico, the
United States Virgin Islands ,British Virgin Islands and theDominican Republic do not have active volcanoes; however they are at risk fromearthquake s andtsunami s.Public awareness
Knowledge of the earthquake and tsunami risks has not been widespread among the general public of the islands located near the trench. Governments have generally spoken little about the risks
Since 1988, the Puerto Rican Seismic Society has been trying to use the Puerto Rican media to inform people about a future earthquake that could result in a catastrophic tragedy.
Following the 2004 tsunami that affected more than forty countries in the
Indian ocean , many more people now fear of the consequences that such an event would bring to the Caribbean. Local governments have begun emergency planning. In the case of Puerto Rico and the U.S. Virgin Islands, theUnited States government has been studying the problem for years [http://pubs.usgs.gov/fs/fs141-00/fs141-00.pdf] and is increasing its seismic investigations and developing tsunami warning systems.Earthquake history
On
11 October 1918 , the western coast of the island was hit by a major earthquake, which is famous in the area, and caused atsunami . In 1953,Santo Domingo ,Dominican Republic , was affected by the Santo Domingo earthquake. Experts blame both tragic earthquakes on the Puerto Rico trench fault.Puerto Rico in particular has always been an area of concern to earthquake experts because, apart from the 1918 episode, there are frequent cases of tremors in and around the island. A 1981 tremor was felt across the island, while another in 1985 was felt in the towns of Cayey and Salinas.
[http://pubs.usgs.gov/fs/fs141-00/fs141-00.pdf]
ee also
*
Plate tectonics
*Caribbean Plate
*Oceanic trench References
External links
* [http://soundwaves.usgs.gov/2003/10/fieldwork.html Sound Waves 03 USGS]
* [http://soundwaves.usgs.gov/2004/06/meetings.html Sound Waves 04]
* [http://woodshole.er.usgs.gov/project-pages/caribbean/ Woods Hole USGS]
* [http://redsismica.uprm.edu/english/ Puerto Rico Seismic Network web site]
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