LAUSR

Significance This study tackles the longstanding question of how the expanding Tibetan Plateau has influenced the continental deformation in east China using an approach that maps seismic azimuthal anisotropy, the directional dependence of seismic wave speeds in the lithosphere and asthenosphere, which are the rigid outer shell and mechanically weak part of the upper mantle, respectively. The results depict the eastward extrusion of asthenosphere beneath northeast Tibet whose motion is being blocked and deflected by Ordos and Sichuan cratonic keels. The consequence is the asthenosphere migrates around the Ordos and then turns into an east-west flow within the narrow channel of thinner lithosphere between these cratons. A broad region of surface continental deformation in eastern China is influenced by this asthenospheric flow.