A Tectonic Breakup in Progress
The Afar Triple Junction is a geological site where three tectonic plates—the Nubian, Somali, and Arabian—are actively pulling apart. This process, known as rifting, is tearing the continent apart. The junction connects three massive rift systems: the Red Sea Rift, the Gulf of Aden Rift, and the East African Rift. While most plate boundaries are hidden deep underwater, the Afar region allows scientists to observe the final stages of continental breakup on dry land.
The forces at play are immense. The Arabian plate is moving away from Africa at a rate of about 17 millimeters per year, while the Somali plate separates from the Nubian plate more slowly, at around 5 mm per year. This stretching of the Earth's crust is driven by a mantle plume, a massive upwelling of hot rock from deep within the Earth, centered beneath the Afar region. This intense heat thins and fractures the lithosphere, creating the vast, low-lying Danakil Depression, which sinks to more than 125 meters below sea level. In about 10 million years, geologists predict the entire East African Rift will be submerged, creating a new ocean basin and turning the Horn of Africa into an island.