Collaborative Research: Advances in African Crust and Upper Mantle Dynamics from Seismology, Geodesy, and Geodynamics

Understanding how the outer shell of the Earth moves and deforms is essential for explaining natural phenomena like earthquakes and volcanic activity. This project seeks to improve knowledge of tectonics by studying the deep structure beneath Africa, a continent that holds key clues about how the interior of the planet influences surface movements. Unusually hot mantle rocks are observed underneath Africa, as well as the East African Rift System, the most prominent and active continental rift on the Earth.

Taking advantage of these features, the project will develop a detailed model of the deep structure beneath this continent. It will also revise how its tectonic plates move, and explore interactions between the Earth's outer shell with the deeper convecting mantle beneath Africa. The results of this research will help increase understanding of fundamental processes shaping our planet.

For example, the findings may enhance earthquake hazard assessments, improve models of global plate motions, and provide relevant information to other aligned fields, such as geothermal exploration. This project uses advanced seismic and geodetic data to provide a more complete picture of Earth's dynamic interior.

This project will try to advance the understanding of plate tectonics by investigating how the African continent interacts with the underlying convecting mantle. Specifically, it will test a long-standing hypothesis that lithosphere-asthenosphere coupling modulates the influence of mantle convection on Africa's surface motions, with broader implications for global tectonic processes.

The research will integrate seismic and geodetic data from AfricaArray, Global Navigation Satellite System (GNSS) stations, and other sources to develop open-access, high-resolution continental-scale models of the kinematics of Africa, crustal and lithospheric structure, upper mantle seismic properties—including azimuthal anisotropy—and key mantle discontinuities. To test this hypothesis, the project will enhance and leverage the capabilities of the open-source software ASPECT (Advanced Solver for Planetary Evolution, Convection, and Tectonics) to enable improved modeling of lithosphere-asthenosphere viscous coupling at a continental scale.

A key objective is to determine whether lithospheric motion in Africa and its surroundings is only weakly coupled to the underlying convecting mantle due to an anomalously hot and low-viscosity upper asthenosphere. Beyond scientific contributions, the project has the following major broader impacts. It will support annual AfricaArray meetings in South Africa and enhance capacity-building efforts through workshops on data science, seismic and GNSS data processing, and access to streaming datasets.

These workshops will follow well-established Carpentries lesson structures, with a focus on training new instructors.. An independent professional evaluation will make sure its impacts are maximized. Undergraduate researchers will contribute to the development of seismic tomography models increasing their technical skills.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.