Role of Lithospheric Buoyancy Forces in Driving Deformation in East Africa From 3D Geodynamic Modeling

Despite decades of investigation, the origin forces driving continental rifting remains highly debated. Deciphering their relative contributions is challenging due to nonlinear and depth-dependent nature lithospheric rheology. Recent geodynamic studies East African Rift (EAR) report contradicting results regarding contribution horizontal mantle tractions buoyancy forces. Here, we use high-resolution 3D regional numerical modeling EAR isolate observed deformation. Modeled surface velocities closely match kinematic models Somalian Plate, Victoria Block, Rovuma Block motions, but provide poor fit along-rift motions in deforming zones. These suggest that primarily drive present-day ?E-W extension across EAR, intrarift deformation may result from viscous coupling asthenospheric flow.