Earthquake Sequence Calculations with Dynamic Weakening Mechanisms

There are multiple lines of evidence that major faults which host large earthquakes (e.g., San Andreas fault) operate at much lower shear stresses than what is predicted by Byerlee's law and a litho- and hydro-static stress state. Recent laboratory experimental studies suggest that a fault weakens dramatically at coseismic slip rates. We have taken the experimentally derived dynamic weakening into account in the earthquake sequence simulations. Our studies reveal that the overall stress level at which a fault operates is controlled by the frictional resistance at coseismic slip rates.