The East African Rift is a network of valleys that stretches from the Red Sea to Mozambique. Here, we see cultivated fields in the Rift Valley of Ethiopia. (Image credit: LuCaAr via Getty Images)

An overhead view of the East African Rift, with a river in a cultivated valley flanked by steep cliffs

So will Africa rip apart completely, and if so, when will it split? To answer this question, let’s look at the region’s tectonic plates, the outer parts of the planet’s surface that can collide with each other, making mountains, or pull apart, creating vast basins.

Along this colossal tear in eastern Africa, the Somalian tectonic plate is pulling eastward from the larger, older part of the continent, the Nubian tectonic plate, according to NASA’s Earth Observatory. (The Somalian plate is also known as the Somali plate, and the Nubian plate is also sometimes called the African plate.)

The Somalian and Nubian plates are also separating from the Arabian plate in the north. These plates intersect in the Afar region of Ethiopia, creating a Y-shaped rift system, the Geological Society of London noted.

A slow break

The East African Rift started forming about 35 million years ago between Arabia and the Horn of Africa in the eastern part of the continent, Cynthia Ebinger, chair of geology at Tulane University in New Orleans and a science adviser to the U.S. State Department’s Bureau of African Affairs, told Live Science. This rifting extended southward over time, reaching northern Kenya by 25 million years ago.

The rift consists of two broadly parallel sets of fractures in Earth’s crust. The eastern rift passes through Ethiopia and Kenya, while the western rift runs in an arc from Uganda to Malawi, the Geological Society of London noted. The eastern branch is arid, while the western branch lies on the border of the Congolese rainforest, according to NASA’s Earth Observatory.

The existence of the eastern and western rifts and the discovery of offshore zones of earthquakes and volcanoes indicate that Africa is slowly opening along several lines, which together amount to more than 0.25 inch (6.35 millimeters) per year, Ebinger said.

“The rifting right now is very slow, about the rate that one’s toenails grow,” Ken Macdonald, a distinguished professor emeritus of Earth science at the University of California, Santa Barbara, told Live Science.