Smith Lecture: Cenozoic Extension, Volcanism and Plateau Uplift in Eastern Africa and the African Superplume
The African superplume is arguably the largest feature in Earth’s lower mantle and whether or not it extends into the upper mantle beneath eastern Africa, giving rise to the Cenozoic rifting, volcanism and plateau uplift found there, has long been debated. New seismic images of mantle structure obtained from modeling AfricaArray data indicate that the superplume is indeed a whole-mantle structure. The images come from body and surface wave tomography, receiver function stacks illuminating topography on the 410 and 660 km discontinuities, and shear wave splitting. The seismic images are consistent with a thermal anomaly of a few hundred degrees spanning the mid-mantle connecting anomalous lower mantle structure under southern Africa with anomalous upper mantle structure under eastern Africa.