California’s seismic hinge. The San Andreas Fault drives plate motion along the Pacific-North American boundary, reshaping landscape and risk.
Recent studies show California’s San Andreas and San Jacinto faults are under stress at levels not seen in a millennium, raising the risk of a large, multi-fault rupture. Cajon Pass could act as a bridge or barrier, and preparedness measures are urged as hazard models improve with physics-based simulations.