Africa’s split closer than thought
A section of eastern Africa has reached a more advanced stage of continental separation than previously believed, raising the prospect of a new ocean forming there in the distant future, reports a Qazinform News Agency correspondent, citing a study published in Nature Communications.
The researchers examined the Turkana Rift Zone, which stretches across Kenya and Ethiopia and forms part of the wider East African Rift System. Seismic measurements showed that the Earth’s crust is about 13 kilometers thick along the rift’s center, compared with more than 35 kilometers farther from it.
“We found that rifting in this zone is more advanced, and the crust is thinner, than anyone had recognized,” said lead author Christian Rowan, a researcher at Columbia University’s Lamont-Doherty Earth Observatory. “Eastern Africa has progressed further in the rifting process than previously thought.”
The findings indicate that Turkana has entered a phase called “necking.” During this stage, the stretching of a continent becomes concentrated along the rift’s axis, thinning and weakening the crust. The study identifies Turkana as an active continental rift undergoing this process, offering scientists an opportunity to examine a stage of separation that has been difficult to observe.
“The thinner the crust gets, the weaker it becomes, which helps promote continued rifting,” Rowan said. Co-author Anne Bécel described the thinning as a critical threshold, adding: “We think this is why it is more prone to separate.”
The researchers estimate that necking began roughly four million years ago, following a period of widespread volcanic activity. A later stage, known as oceanization, could eventually create new seafloor as the continent pulls apart. That transition is expected to take several million more years; the findings do not signal an imminent split on a human timescale.
The study may also shed light on why Turkana has yielded such a rich record of early human life. As the rift developed, the land subsided and sediment accumulated more rapidly, creating conditions that could preserve fossils. The timing coincides with the beginning of extensive, continuous fossil-bearing deposits in the region.
“The conditions were right to preserve a continuous fossil record,” Rowan said. The team suggests Turkana’s abundance of fossils may partly reflect those geological conditions, though further research is needed to test the connection between rifting and the record of human evolution.
Earlier, Qazinform News Agency reported that a study based on global satellite positioning data found that Earth is gradually becoming less flattened at the poles, while its gravity field is becoming more flattened at the equator.