Cocos plate

The Cocos plate is a young piece of the ocean floor. It sits under the Pacific Ocean near Central America. This plate gets its name from Cocos Island. That small island sits right on top of it. Only one piece of land stays above the water on this plate. This is Cocos Island, which belongs to Costa Rica. It is about 550 km southwest of the Costa Rican mainland.

This plate moves in a very specific way. It is pushed eastward from the East Pacific Rise. As it moves, it slides under the Caribbean plate. Scientists call this movement subduction. The edge of the plate heats up as it goes down. It also adds water to the mantle layer above it. This water makes rock melt into magma. This magma stays under great pressure.

This movement creates many interesting things on land. The melting rock forms the Central America Volcanic Arc. This is a long line of volcanoes. They stretch from Costa Rica all the way to Guatemala. The movement also causes many earthquakes. These shakes can be very strong. A big earthquake hit Mexico City in 1985. Another one hit Chiapas in 2017.

We can look back to see how this plate began. It formed about 23 million years ago. A large plate called the Farallon plate broke into two pieces. This event also created the Nazca plate. Later, the Cocos plate broke again. This created a tiny piece called the Rivera plate. The Rivera plate became its own small plate about 5 to 10 million years ago.

The Cocos plate has many different neighbors. To the northeast, it meets the North American and Caribbean plates. The Pacific plate is to its west. The Nazca plate sits to its south. The boundary with the North American plate is the Middle America Trench. The eastern side has the Panama fracture zone. The southern side is the Cocos–Nazca spreading centre.