The Red Sea: Birth of an Ocean

Nowhere on the present-day Earth can the transition from a continental to an oceanic rift be observed and studied better than in the Red Sea region, where three rifts in different stages of evolution meet in a triple point located in the Afar region. A thermal and/or compositional mantle plume may have risen from the upper mantle below Afar already at ~30 Ma, and may have triggered, at least in part, the rifting process. The axial area of the rifts is marked by intense seismicity. While the East African is a fully continental rift, the Gulf of Aden rift experienced oceanic crust accretion between Arabia and Somalia starting already at 17 Ma with a progressive westward propagation that impacted against Africa in the Afar Triangle starting at <1 Ma. The axial zone of oceanic crustal accretion in the Gulf of Aden is segmented by several small (