Plate tectonics continually reshape Earth's surface, breaking apart continents over millions of years.
In this study, J.O.S. Hammond and colleagues use seismology to image beneath the Afar depression, the northern extreme of the East Africa rift and the only place on land undergoing the final stages of continental breakup.
They record distant earthquakes on seismometers deployed across East Africa and, much like a doctor uses X-rays, use this energy to build 3-D images of Earth structure to depths of 400 km. These tomographic images show that sharp changes in rift orientation at the surface are mimicked 75 km deep in the mantle.
Hammond and colleagues show that narrow hot zones and regions of upwelling material beneath the stretched and thinned rift zone produce melt, supplying volcanoes in the region and feeding the formation of new oceanic crust in Afar.
J.O.S. Hammond et al., Department of Earth Science and Engineering, Imperial College London, DOI: 10.1130/G33925.1