Fig. 4
From: Rheology and stress in subduction zones around the aseismic/seismic transition
Pattern of flow in a subduction channel. This is a combination of Couette flow (simple shear) driven by the subducting plate, and Poiseulle flow (channelized flow) driven by a pressure gradient produced by the buoyancy of the subducted sediment and the arc-trench topographic gradient. Dashed black line indicates the locus of maximum exhumation rate, across which the sense of shear changes, as shown. Thickness of channel estimated for the Pelona Schist from seismic tomographic data in southern California (Lee et al. 2014)