Reconciling surface plate motions with rapid three-dimensional mantle flow around a slab edge

A central axiom of the theory of plate tectonics is that the surface plates are coupled to, and carried along by, convection in the Earth's mantle. The situation is rather different at subduction zones, however. Margarete Jadamec and Magali Billen now present calculations that quantify this variance. They use three-dimensional numerical models of buoyancy-driven deformation with realistic slab geometry for the Alaska subduction-transform system...