Effect of Surface Morphology on the Dissipation During Shear and Slip Along a Rock-Rock Interface that Contains a Visco-elastic Core

摘要

High resolution topography measurements of the Vuache-Sillingy fault (Alps, France) reveal a characteristic roughness of the fault zone. We investigate the effect of roughness on the rheology of a planar shear configuration by using a model system consisting of a visco-elastic layer embedded into a rigid solid. The model is discussed in the context of several geological cases: a damage fault zone, a fault smeared with a clay layer, and a shear zone with strain weakening. Using both analytical approaches and finite element simulations, we calculate to linear order the relation between wall roughness and the viscous dissipation in the fault zone as well as the average shear rate.