The effects of pre-stress assumptions on dynamic rupture with complex fault geometry in the San Gorgonio Pass, California, region

Abstract We use three-dimensional (3-D) dynamic finite-element models to investigate potential rupture paths of earthquakes propagating along faults through the western San Gorgonio Pass, a structurally complex region Andreas fault system in southern California (USA). focus on right-lateral Bernardino strand system, oblique thrust–right-lateral Pass zone, and portion Garnet Hill system. 3-D method model propagation geometry that reflects current understanding local geometrical complexity is consistent with long-term loading observed surface deformation. test three different types pre-stress assumptions: (1) constant tractions (assuming pure strike-slip motion strands zone), (2) uniform regional stress regime, (3) (evolved) from quasi-static crustal deformation modeling. Our results imply under more realistic evolved assumptions, throughgoing southeast northwest (i.e., strand) may be likely than reverse direction (from strand). The have implications for earthquake as well ground Los Angeles Basin. also emphasize how patterns combine influence systems.