African plate

The African plate, also known as the Nubian plate, is a major tectonic plate that includes most of the continent of Africa (except for its easternmost part) and the ocean floor nearby to the west and south. It also covers a thin strip of Western Asia along the Mediterranean Sea, including parts of Israel, Palestine, and Lebanon.

This plate is surrounded by several other plates. To the west, it is separated from the North American plate and South American plate by the Mid-Atlantic Ridge. To the east lies the Arabian plate and the Somali plate. To the north, it meets the Eurasian plate, Aegean Sea plate, and Anatolian plate. And to the south, it borders the Antarctic plate.

Between about 60 million years ago and 10 million years ago, the Somali plate started to move away from the African plate along the East African Rift. Because Africa includes land from both the African and Somali plates, some writers call the African plate the Nubian plate to tell them apart.

Boundaries

The African plate touches many other plates around it. On the west, it meets the North American plate and the South American plate at the Mid-Atlantic Ridge, where new land is forming. On the east, it is next to the Arabian plate and the Somali plate. To the north, it is close to the Eurasian plate, the Aegean Sea plate, and the Anatolian plate. To the south, it meets the Antarctic plate at the Southwest Indian Ridge. Most of these places are where the Earth's plates are moving apart, except for the northern edge and a small part near the Azores called the Terceira Rift.

Components

The African plate is made up of several strong, old pieces of land called cratons and less stable pieces called terranes. These pieces came together to form the African continent a very long time ago. The main cratons, from south to north, are the Kalahari Craton, Congo Craton, Tanzania Craton, and West African Craton. These cratons were far apart in the past but joined together and stayed connected.

Some areas of the cratons are covered by layers of sediment, such as in the Tindouf Basin, Taoudeni Basin, and Congo Basin. The plate also has places where the land moves, like the Central African Shear Zone and rifts such as the Anza Trough.

Modern movements

The African plate is slowly moving and splitting in the eastern part of Africa along the East African Rift. This area separates the African plate from the Somali plate to the east. Scientists have different ideas about why this is happening—one idea is that a deep heat source called a mantle plume under the Afar region is pushing the earth's surface outward. Another idea is that the earth's crust is breaking along a weak line as plates to the east move quickly northward.

The African plate moves about 2.15 cm (0.85 in) every year. Over the last 100 million years, it has been moving toward the northeast. This movement is bringing it closer to the Eurasian plate, which causes the earth's oceanic crust to move under the continental crust in places like the Mediterranean. In the western part of the Mediterranean, the movement between the Eurasian and African plates creates both side-to-side and pushing forces in an area called the Azores–Gibraltar Fault Zone. Along its northeast edge, the African plate meets the Red Sea Rift, where the Arabian plate is moving away from it.

A place of intense heat called the New England hotspot in the Atlantic Ocean may have formed a line of underwater mountains on the African plate a long time ago, but it does not seem to be active now.