Cocos Plate


Cocos Plate
Detail of the Cocos and Caribbean plates
Detail of tectonic plates from: Tectonic plates of the world
Detail of the Cocos and Caribbean plates. From: Plate tectonics map

The Cocos Plate is an oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it.

Contents


Geology

The Cocos Plate is created by sea floor spreading along the East Pacific Rise and the Cocos Ridge, specifically in a complicated area geologists call the Cocos-Nazca spreading system. From the rise the plate is pushed eastward and pushed or dragged (perhaps both) under the less dense overriding Caribbean Plate, in the process called subduction. The subducted leading edge heats up and adds its water to the mantle above it. In the mantle layer called the asthenosphere, mantle rock melts to make magma, trapping superheated water under great pressure. As a result, to the northeast of the subducting edge lies the continuous arc of volcanos stretching from Costa Rica to Guatemala and a belt of earthquakes that extends farther north, into Mexico.

The northern boundary of the Cocos Plate is the Middle America Trench. The eastern boundary is a transform fault, the Panama Fracture Zone. The southern boundary is a mid-oceanic ridge, the Galapagos Rise.[1] The western boundary is another mid-ocean ridge, the East Pacific Rise.

The Cocos and Nazca Plates are the remnants of the former Farallon Plate, which broke up about 23 million years ago. A hotspot under the Galapagos Islands lies along the Galapagos Rise. (see Galapagos hotspot)

The Rivera Plate north of the Cocos Plate is thought to have separated from the Cocos Plate 5-10 million years ago. The boundary between the two plates appears to lack a definite transform fault, yet they are regarded as distinct.

The devastating 1985 Mexico City earthquake was a result of the subduction of the Cocos Plate beneath the North American Plate. The also devastating 2001 El Salvador earthquakes were generated in the subduction of this plate on the Caribbean Plate

References

External links



Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Cocos Plate — Geol. a tectonic division of the earth s crust, coincident with the oceanic Guatemala Basin, and bounded on the north and east by the Central American Trench, on the west by the East Pacific Rise, and on the south by the Nazca Plate. * * * …   Universalium

  • Cocos Plate — Geol. a tectonic division of the earth s crust, coincident with the oceanic Guatemala Basin, and bounded on the north and east by the Central American Trench, on the west by the East Pacific Rise, and on the south by the Nazca Plate …   Useful english dictionary

  • Cocos — may refer to: Cocos (genus), a plant genus with the coconut as its only accepted species Cocos Lagoon, south of Guam Cocos Malays, an ethnic group inhabiting the Cocos (Keeling) Islands Cocos Plate, a tectonic plate beneath the Pacific Ocean… …   Wikipedia

  • Plate tectonics — The tectonic plates of the world were mapped in the second half of the 20th century …   Wikipedia

  • Cocos Island — For other uses, see Cocos Island (disambiguation). Cocos Island National Park * UNESCO World Heritage Site Cocos Island …   Wikipedia

  • Cocos (plaque tectonique) — Plaque de Cocos Pour les articles homonymes, voir Cocos. Plaque de Cocos Éponyme …   Wikipédia en Français

  • Nazca Plate —   The Nazca plate, shown in light blue Full size image showing all plates The Nazca Plat …   Wikipedia

  • North American Plate —   The North American plate, shown in brown The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahama …   Wikipedia

  • Caribbean Plate — The Caribbean Plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the north coast of South America. Roughly 3.2 million square kilometers (1.2 million square miles) in area, the Caribbean Plate borders… …   Wikipedia

  • South American Plate — The South American Plate is a tectonic plate covering the continent of South America and extending eastward to the Mid Atlantic Ridge. The easterly side is a divergent boundary with the African Plate forming the southern part of the Mid Atlantic… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.