Deep African mantle plume drives unexpected sideways motion in East African Rift

A study integrating more than 12 years of precise GPS measurements with 3D thermomechanical models shows that the African Superplume—a huge column of hot mantle material rising from deep beneath southwest Africa toward the northeast—drives northward mantle flow that produces deformation parallel to the East African Rift. Traditional lithospheric buoyancy forces account for the expected perpendicular stretching but cannot explain the observed rift-parallel motion or the matching seismic anisotropy.

The simulations reproduce both the anomalous surface motion and the alignment of seismic waves, indicating deep mantle dynamics play a significant role alongside shallower forces. Lead author Tahiry Rajaonarison and associate professor D. Sarah Stamps argue this dual-force scenario reshapes our understanding of continental breakup. Their findings offer new insight into how continents begin to split and improve predictions of related geological hazards.