Influence of fault bends on ruptures

Data on slip along the San Andreas Fault have been examined to understand the influence of a bend in the fault system on the extent of slip release. A correlation of slip along the fault in the great 1906 and 1857 earthquakes with fault geometry shows that maximum slip occurred near a major change in the fault strike and may be a function of this change. The data appear to suggest that, in general, it takes about 10 years of strain accumulation to negotiate a 1° change in fault strike, assuming a slip rate of about 3 cm/yr. Seismic hazard along the San Andreas Fault may therefore also be a function of fault geometry.