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We propose a model for earthquake afterslip based on rate and state variable friction laws. In the model, afterslip is attributed to the interaction of a velocity‐weakening region at depth (within which earthquakes nucleate) with an upper region of velocity‐strengthening frictional behavior. The existence of this upper region is supported by independent seismologic observations and the results of laboratory friction experiments. In our model, afterslip is the result of relaxation of a stress perturbation within the velocity‐strengthening region, which arises when an earthquake propagates into that region from below. We derive the stress perturbation and its decay from the friction constitutive law using a simple, 1 degree‐of‐freedom approximation for the elastic interaction between the fault and its surroundings. This approximation is based on thickness‐averaged displacements and slip velocities within the velocity …