Effects of fault interaction on moment, stress drop, and strain energy release.

Solutions for colinear shear cracks are used to examine quantitatively the effects of fault slip zone interaction on determinations of moment, stress drop, and static energy release. Two models, the barrier model and the asperity model, are considered. In the asperity model, the actual distribution of strengths on a fault plane is idealized as a combination of two limiting cases; areas which slip freely at a uniform value of a residual friction stress and unbroken ligaments or 'asperities' across which slip occurs only at the time of a seismic event. In the barrier model, slip zones separated by unbroken ligaments (barriers) are introduced into a uniformly stressed medium to approximate the non-uniform fault propagation proposed by Das and Aki.-Authors