How Caribbean islands arc was formed

The movement of Earth's viscous mantle against South America has pushed the Caribbean islands east over the last 50 million years, according to a study published Monday in the journal Nature Geoscience.

The University of Southern California, in announcing the study, said the findings upend previous hypotheses of the seismic activity beneath the Caribbean Sea and provide an important new look at the unique tectonic interactions that are causing the Caribbean plate to tear away from South America.

The Caribbean plate is being pushed eastward due to a thick section of the South American plate called a "cratonic keel." This section of crust is three times thicker than its surroundings.

Meanwhile, part of the South American plate is being pushed beneath the Caribbean plate, a process called subduction. Intense heat and pressure gradually force water-containing magma to rise into the Earth's mantle and fuel the many active volcanoes in the region.

All of this pushing and pulling formed the distinctive arc shape of the Caribbean islands and has created a very complex system of faults between the two plates, in northern South America, according to the USC statement. The study mapped several of these strike-slip faults, which are similar to California's San Andreas Fault.

1. Science news from NBCNews.com

   1. Cast a vote for your favorite robots

      Science editor Alan Boyle's blog: For the past nine years, the Robot Hall of Fame has relied solely on expert judges to dole out its honors ? but this time, the people will get their say.

   2. 'Baywatch' star ends Noah's Ark search
   3. Eww! Newly discovered rat has no back teeth
   4. Archaeologist digs into Nazi death camp

Recent earthquakes in the area helped the two researchers develop an image of the Earth's deep interior. The earthquake waves move slower or quicker depending on the temperature and composition of the rock.

"Studying the deep Earth interior provides insights into how the Earth has evolved into its present form," researcher Meghan S. Miller said in the statement.

For their study, the researchers used earthquake data to develop 176 computer models, USC said.

Follow OurAmazingPlanet on Twitter? @OAPlanet.? We're also on? Facebook? and? Google+.

? 2012 OurAmazingPlanet. All rights reserved. More from OurAmazingPlanet.

Source: http://www.msnbc.msn.com/id/48744032/ns/technology_and_science-science/

jeb bush sherry arnold snooty fox el debarge portland weather clintonville battlestar galactica blood and chrome