The Danakil Depression

Beneath the Horn of Africa, three tectonic plates are quietly failing to agree. The Nubian, the Somali and the Arabian plates meet at what geologists call the Afar Triple Junction, and since the Late Eocene to Early Oligocene, roughly 30 to 34 million years ago, they have been pulling apart. By the Early Miocene, about 20 million years ago, Africa and Arabia had fully broken apart along this line, opening the Red Sea and Gulf of Aden rifts alongside the Main Ethiopian Rift. The three arms still meet here, and nowhere else on Earth can this late-stage rifting be studied on dry land. The plates keep separating today, about 1 to 2 centimeters a year, patient enough that no one notices it happening. A separate wedge of crust, the Danakil microplate, has been twisting counterclockwise against Africa at about 1.9 degrees per million years since roughly 9 to 11 million years ago. The ground here is not solid. It is a slow-motion tear.