This course will focus on the study of the physical processes that occur on active fault systems over various time and spatial scales. Topics that will be addressed include brittle fracture of rocks, fault friction, macroscopic failure criteria, effective stress laws, rheology, friction constitutive laws and a detailed description of the theory of rupture nucleation and propagation. Processes of earthquake rupture and instability conditions will also be developed in the context of an energy balance for faulting. Other topics include earthquake source parameters and scaling laws, the processes leading up to and following seismic rupture and earthquake triggering. Seismic and aseismic faulting.