Africa could split apart sooner than scientists thought

Africa could divide sooner than scientists thought

By Adam Kovac edited by Claire Cameron

Part of East Africa is “ready” to break away from the rest of the continent much sooner than scientists previously imagined, according to new research.

The place in question is the Turkana Rift, which stretches 500 kilometers across Kenya and Ethiopia. The rift is just one segment of the East African Rift System, where three tectonic plates meet. Two of these plates are separating at the Turkana Rift, a process that will eventually cause the continent to split in two, creating a new ocean between the separated lands. These same forces may have made the Turkana Rift a site rich in discoveries of ancient human fossils, like the famous Turkana boy.

Now, a new study published in Natural communications Thursday, discovered that the Earth’s crust at the fault is much thinner than scientists thought.

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“We found that the rifting in this area is more advanced and the crust is thinner than anyone had imagined,” said the study’s lead author, Christian Rowan, a Ph.D. student in Earth and environmental sciences at Columbia University, in a press release. “East Africa has progressed further in the process of division than previously thought. »

Rowan and his colleagues combined the field observations with high-resolution seismic reflection, a technique that involves sending sound waves through the ground and analyzing the signal that bounces back. Geologists have known for some time that Africa is destined to become two separate continents, but the results indicate the process is further along than they imagined. The Earth’s crust in the center of the rift is only 13 kilometers deep, much shallower than in more distant areas, more than 35 kilometers deep. This is a sign that the crust in the center is shrinking, meaning the middle of the fault is getting thinner and weaker as the two sides separate.

The team also found signs of previous cracking in the area that likely weakened the crust further. The study “challenges some of the most traditional ideas about how continents break apart,” Rowan said.

The fault appears to have reached a “critical threshold,” Anne Bécel, a geophysicist at the Lamont-Doherty Earth Observatory in Colombia and co-author of the study, said in the same statement.

The continent is not at imminent risk of rupture, however: the divide began to tear about 45 million years ago, and researchers estimate that it will take a few more million years to break apart. That’s a long time for humans and a blink of an eye for the planet.

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