Crustal structure across the San Andreas Fault, southern California from teleseismic converted waves

Crustal structure along a 140 km long profile across the San Andreas Fault (SAF) in southern California was imaged by stacking teleseismic P–S converted phases recorded by a dense, short-period seismic array. The crust/mantle discontinuity (Moho) is visible as a continuous feature at a depth around 30 km but is offset 6 to 8 km beneath the SAF. A small Moho disruption can also be seen under the Eastern California Shear Zone (ECSZ). These results suggest that the SAF and ECSZ extend through the entire crust. The Moho upwarp under the San Gabriel Mountains indicates that the mountain ranges were lifted en masse as a result of crustal buckling under horizontal compression.