East Africa Might Break Off From the Continent Sooner Than Scientists Thought—and a New Ocean May Fill the Gap

A new study suggests that a rift in Kenya and Ethiopia has reached a critical stage in the split-up process, and that water may flood it in a few million years

Margherita Bassi | Daily Correspondent

May 8, 2026 2:48 p.m.

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Around 250 million years ago, Earth’s modern-day landmasses were united in a supercontinent called Pangea. But the planet’s shifting outer layer—the crust—eventually broke it apart, according to the well-established scientific theory of plate tectonics.  

The theory proposes that huge rock slabs called tectonic plates float atop a molten mantle layer. These plates can move away from each other at locations called rifts, allowing magma to rise and become part of the crust and form new geologic features.

Now, researchers have found that a rift in eastern Africa, which spans Kenya and Ethiopia, seems to be further along in the breakup process than previously thought—and that an ocean will eventually fill the gap. The findings, published April 23 in the journal Nature Communications, suggest that it is the only known active rift in a key phase before forming an ocean basin, and could help explain why the region has preserved such remarkable fossils.

“In essence, we now have a front row seat to observe a critical rifting phase that [has] fundamentally shaped all rifted margins across the world,” says co-author Folarin Kolawole, a geologist at Columbia University, in a statement.

Kolawole and his colleagues investigated the Turkana Rift, which is a roughly 300-mile-wide zone where two tectonic plates are moving apart at a speed of about one-fifth of an inch per year. This zone is part of the larger East African Rift System, which averages about 35 miles wide and stretches for around 4,000 miles from Jordan to Mozambique.

The team examined the section by looking at how acoustic waves bounced off underground layers and integrating that information with other imaging data from below the surface. Then, they generated a map to show the sediment structure and the depth of the top of the crust in the Turkana Rift.

In the center of the rift, the crust is roughly 8 miles thick—far thinner than the more-than-22-mile-thick crust farther away, the team found. This difference is characteristic of “necking,” a phase prior to ocean formation in which the Earth’s crust is being stretched like taffy, resulting in a thin middle.

While not all rifting episodes result in landmasses splitting up, “identification of necking in the [East African Rift System] indicates that eastern Africa is primed for continental breakup,” the authors write in the study. Necking probably began around four million years ago in the wake of widespread volcanic eruptions, the team posits. Additionally, they suspect that geologic activity created fine-grained sediments that rapidly preserved hominin fossils, such as the Turkana Boy, a 1.6-million-year-old Homo erectus skeleton, the most complete one of an archaic human found thus far.

“The conditions were right to preserve a continuous fossil record,” study co-author Christian Rowan, a geoscientist at Columbia University, says in the statement.

In a few million years, the team suspects, magma will rise between the rifting tectonic plates and form a new seafloor. Water will rush in from the Indian Ocean to create a new ocean that divides what’s now the African continent.

Understanding necking, a crucial step in rifting, helps researchers reveal bygone vegetation, landscapes and climates. And in this case, the volcanism that kicked off the process appears to have preserved a trove of more than 1,200 discovered hominin fossils spanning the past four million years.

“What our study has done is looked actually at the rift itself, the structure of the rift there and the processes that are ongoing—and have tied that to the fossil record, to understand how this world-famous fossil record has come to be,” Rowan tells ABC News’ Julia Jacobo.

Margherita Bassi | Read More

Margherita Bassi is a freelance journalist and trilingual storyteller. Her work has appeared in publications including BBC Travel, Discover magazine, Live Science, Atlas Obscura and Hidden Compass.