Continental transform fault between Pacific and North American plates
A cluster of tremors has struck eastern Tehran province, near major fault lines including the Mosha fault. Authorities and seismologists warn that Tehran’s vulnerability stems from active faults, dense urban development and limited preparedness. One quake has been reported at magnitude 4.6 with no casualties so far; experts say the situation may signal future seismic risk for the capital.
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.