Model seismicity: Rupture parameters, stress, and energy relations

For a sequence of shocks of various sizes generated in a laboratory model of a seismic fault, the potential energy released in a shock is well correlated with the associated rupture parameters of length and displacement. The stress drop associated with a shock increases monotonically with the size of the shock. Tsuboi's hypothesis on the approximate constancy of potential energy density before a shock is found to be valid. A better approximation, however, is to assume that the average stress on the fault immediately before and after the shock is constant. Large shocks, although few in number, are responsible for a large fraction of the total energy release.