Co-seismic rupture process of the large 2019 Ridgecrest earthquakes from joint inversion of geodetic and seismological observations

Chengli Liu, Thorne Lay, Emily E. Brodsky, Kelian Dascher-Cousineau, & Xiong Xiong

Submitted August 15, 2019, SCEC Contribution #9841, 2019 SCEC Annual Meeting Poster #277

On 4 July 2019 and 6 July 2019, two large strike-slip earthquakes with W-phase moment magnitudes MWW 6.5 (foreshock) and MWW 7.1 (mainshock) struck the Eastern California Shear Zone, northeast of Ridgecrest. The faulting geometry and kinematic co-seismic slip distribution of both events are determined by jointly inverting seismological and geodetic observations guided by aftershock and surface rupture locations. The foreshock ruptured two orthogonal faults with a prominent L-shaped geometry with maximum slip of ~1.1 m on the NE-SW segment. The mainshock faulting extended NW-SE along several primary fault segments that straddle the foreshock slip. The surface rupture and slip model are mostly near-horizontal strike-slip with maximum slip of ~3.7 m, but there is localized vertical dip-slip motion. Both the foreshock and mainshock ruptures terminate in regions of complex surface offsets. High aftershock productivity and low rupture velocity may be the result of rupture of a relatively immature fault system.

Citation
Liu, C., Lay, T., Brodsky, E. E., Dascher-Cousineau, K., & Xiong, X. (2019, 08). Co-seismic rupture process of the large 2019 Ridgecrest earthquakes from joint inversion of geodetic and seismological observations. Poster Presentation at 2019 SCEC Annual Meeting.


Related Projects & Working Groups
Ridgecrest Earthquakes