Stress orientations at intermediate angles to the San Andreas Fault, California

摘要: [1] There are currently two competing models for the frictional strength of San Andreas Fault in California: strong-fault model and weak-fault model. The predicts maximum horizontal compressive stress axis to be at low angles fault, while relatively weak fault it high angles. Previous studies have disagreed as which is supported by observed orientations. We review compare these present results from several new focal mechanism inversions. find that orientations different generally consistent, implying disagreement one interpretation. majority intermediate not strictly consistent with either current acceptable if assumed a nonoptimally orientated fails because optimally oriented, preexisting planes present. propose alternative better explain orientations: an intermediate-strength all major active faults weak.