Erte Ale Summit Crater, Ethiopia Oldoinyo Lengai, East African Rift ZoneOldoinyo Lengai, East African Rift Zone [
Map of East Africa showing some of the historically active volcanoes(red triangles) and the Afar Triangle (shaded, center) - - a so-called triple junction (or triple point ), where three plates are pulling away from one another: the Arabian Plate, and the two parts of the African Plate (the Nubian and the Somalian) splitting along the East African Rift Zone. USGS website
This image shows several fault scarps that are progressively farther away. Essentially we are looking at the edges of several horst (risen) blocks from within a graben (valley) that contains Lake Baringo.
Boundaries between two plates that are colliding There are 3 types…
Ocean plate colliding with a less dense continental plate Subduction Zone: where the more dense plate slides under the less dense plate VOLCANOES occur at subduction zones; trenches
Slab pull - Cold, sinking lithosphere at the edges of a tectonic plate pulls the rest of the plate across earth’s surface. Ridge push – Gravity pulls newly formed lithosphere downward and away from the mid-ocean ridge. The rest of the plate moves because of this force.