Cocos Tectonic Plate

The Cocos Plate is a relatively small-sized, triangular-shaped oceanic plate located beneath the Pacific Ocean, off the west coast of Central America. It is named after Cocos Island, the only emergent island on the plate.

Several other plates border this plate: the Caribbean Plate and North American Plate to the northeast, the Pacific Plate to the west, and the Nazca Plate to the south.

The boundary between the Cocos Plate and the North American Plate is convergent. The boundary with the Caribbean Plate is also convergent. However, the borders between the Cocos, Nazca, and South American plates form divergent boundaries.

Approximately 23 million years ago, the ancient oceanic Farallon Plate broke into two pieces, creating the Nazca and Cocos plates. Likewise, the Cocos Plate broke into two parts, making the small Rivera Plate.

The Cocos Plate is subducting under Mexico and Central America. As a result, a belt of volcanoes extends from northern Panama to western Mexico, and virtually all of the highest mountains in this belt are volcanic.

These volcanoes are built on the thickened crust, but the principal tectonic process that has affected the landscape is volcanism. These continuous arcs of volcanos are known as:

• the Central America Volcanic Arc, which stretches from Guatemala south into El Salvador, Nicaragua, and Costa Rica and just past the border into northern Panama

• the Trans-Mexican Volcanic Belt, which extends east-west through Mexico

The northern boundary of the 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 Galápagos Rise. The western boundary is another mid-ocean ridge, the East Pacific Rise.

Subduction beneath the North American Plate, along the Middle American Trench in Mexico, generates large earthquakes and sometimes tsunamis every 30 - 100 years.

_{Map illustrating the Cocos plate location relative to the other plates of the Americas}