Comparison of the BSM, the pBSM, and the ESPM. The trench is defined by the intersection of the free surface (horizontal solid line) and the (upper) dipping line; cross-sectional geometry is assumed to be identical along strike; D_lock is the depth to the downdip end of the locked megathrust; x_lock represents the surface projection of the downdip end of the locked megathrust; is the dip of the plate interface; H is the plate thickness in the ESPM; x_G, represents the typical range for the location of the nearest geodetic observation from the trench. The arrows represent relative motion at the plate boundary.