A map of East Africa showing some of the historically active volcanoes (as red triangles) and the Afar Triangle (shaded at the center), which is a so-called triple junction (or triple point) where three plates are pulling away from one another: the Arabian plate and two parts of the African plate—the Nubian and Somali—splitting along the East African Rift ZoneMain rift faults, plates, plate boundaries, GPS plate velocities between adjacent blocks and minimum horizontal stress directions
The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa. The EAR began developing around the onset of the Miocene, 22–25 million years ago.[1] It was formerly considered to be part of a larger Great Rift Valley that extended north to Asia Minor.
A narrow zone, the rift is a developing divergenttectonic plateboundary where the African plate is in the process of splitting into two tectonic plates, called the Somali plate and the Nubian plate, at a rate of 6–7 mm (0.24–0.28 in) per year.[2] The rift system consists of three microplates, the Victoria microplate to the north, and the Rovuma and Lwandle microplates to the south. The Victoria microplate is rotating anti-clockwise with respect to the African plate. Its rotation is caused by the configuration of mechanically weaker and stronger lithospheric regions in the EARS.[3][4]