Towards the Afar region, however, the entire rift valley floor is covered with volcanic rocks. This suggests that, in this area, the lithosphere has thinned almost to the point of complete break up. When this happens, a new ocean will begin forming by the solidification of magma in the space created by the broken-up plates. Eventually, over a period of tens of millions of years, seafloor spreading will progress along the entire length of the rift. The ocean will flood in and, as a result, the African continent will become smaller and there will be a large island in the Indian Ocean composed of parts of Ethiopia and Somalia, including the Horn of Africa.

Dramatic events, such as sudden motorway-splitting faults or large catastrophic earthquakes may give continental rifting a sense of urgency but, most of the time, it goes about splitting Africa without anybody even noticing.

Lucia Perez Diaz, Postdoctoral Researcher, Fault Dynamics Research Group, Royal Holloway

This article was originally published on The Conversation. Read the original article.

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