- East Pacific Rise
The East Pacific Rise is a
mid-oceanic ridge , a divergent tectonic plate boundary located along the floor of thePacific Ocean . It separates thePacific Plate to the west from (north to south) theNorth American Plate , theRivera Plate , theCocos Plate , theNazca Plate , and theAntarctic Plate . It runs from an undefined point nearAntarctica in the south northward to its termination at the northern end of theGulf of California in theSalton Sea basin in southernCalifornia .Overview
The
oceanic crust is moving away from the East Pacific Rise to either side. On the eastern side the eastward moving plates meet the westward movingSouth American Plate and theNorth American Plate and are being subducted under them. The belt ofvolcano es along theAndes and the arc of volcanoes throughCentral America andMexico are the direct results of this collision. Due east of the Baja California Peninsula, the newly-formed crust from the Rise appears to be in a transition which is thus far geologically undefined, but may become a subduction zone as well.Near
Easter Island , the East Pacific Rise meets theChile Rise at the Easter Island and Juan Fernandez microplates, trending off to the east where it subducts under theSouth American Plate at thePeru-Chile Trench along the coast of southernChile . The southern extension of the East Pacific Rise (called thePacific-Antarctic Ridge ) merges with theSoutheast Indian Ridge at theMacquarie Triple Junction south ofNew Zealand .Along the East Pacific Rise the
hydrothermal vent s calledblack smoker s were first discovered and have been extensively studied. These vents are formingvolcanogenic massive sulfide ore deposit s on the ocean floor. Many strange deep-water creatures have been found here. The southern stretch of the East Pacific Rise is one of the fastest-spreading sections of the Earth'smid-ocean ridge system.References
External links
* [http://marineemlab.ucsd.edu/Projects/EPR2004/ Scripps Institution of Oceanography East Pacific Rise Marine EM website]
* [http://www.earth.columbia.edu/news/2002/story12-05-02.html Galapagos rise and microplate]
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