Source parameters for the 1952 Kern County earthquake, California: A joint inversion of leveling and triangulation observations

Coseismic leveling and triangulation observations are used to determine the faulting geometry and slip distribution of the July 21, 1952, M_w 7.3 Kern County earthquake on the White Wolf fault. A singular value decomposition inversion is used to assess the ability of the geodetic network to resolve slip along a multisegment fault and shows that the network is sufficient to resolve slip along the surface rupture to a depth of 10 km. Below 10 km, the network can only resolve dip slip near the fault ends. The preferred source model is a two-segment right-stepping fault with a strike of 51° and a dip of 75° SW. The epicentral patch has deep (6-27 km) left-lateral oblique slip, while the northeastern patch has shallow (1-12.5 km) reverse slip. There is nearly uniform reverse slip (epicentral, 1.6 m; northeast, 1.9 m), with 3.6 m of left-lateral strike slip limited to the epicentral patch. The seismic moment is M₀ = 9.2 ± 0.5 × 10¹⁹ N m (M_w = 7.2). The signal-to-noise ratio of the leveling and triangulation data is reduced by 96% and 49%, respectively. The slip distribution from the preferred model matches regional geomorphic features and may provide a driving mechanism for regional shortening across the Comanche thrust and structural continuity with the Scodie seismic lineament to the northeast.