Megathrust locking (${\dot{s}}_{\mathrm{deficit}}=V_{\mathrm{convergence}}-{\dot{s}}_{\mathrm{fault}}$)

Suppression of relative slip on part of a megathrust during an interval of plate convergence, producing a slip deficit and elastic deformation. GNSS, leveling and offshore geodesy constrain it through a fault-geometry and deformation model. A locking fraction is therefore an inferred kinematic quantity; it is not a direct measurement of friction or the magnitude of the next earthquake.