Mantle plumes, columns of very hot material in Earth's mantle, drive volcanic activity and transfer heat from Earth's core to the upper mantle. A new midmantle plume has now been detected below southern Africa. Sun et al. analyzed data from multiple events recorded by a seismic array in the Kaapvaal region of southern Africa. They found a narrow (less than ∼150 kilometers in diameter) plume-like feature starting in the lower mantle at the top of the African large low-velocity structure, a region where mantle composition changes and seismic waves slow down.