On the Rupture Propagation of the 2019 M6.4 Searles Valley, California, Earthquake, and the Lack of Immediate Triggering of the M7.1 Ridgecrest Earthquake

Authors

Jordan T. Cortez, University of California, Riverside
David D. Oglesby, University of California, Riverside
Christodoulos Kyriakopoulos, University of Memphis
Baoning Wu, University of California, Riverside
Kuntal Chaudhuri, University of California, Riverside
Abhijit Ghosh, University of California, Riverside
Roby Douilly, University of California, Riverside

Abstract

The 2019 M6.4 Searles Valley, Southern California, earthquake nucleated on a buried right-lateral fault segment and propagated around a perpendicular fault intersection to a surface-outcropping left-lateral segment, but it did not propagate coseismically to the intersecting fault of the subsequent M7.1 Ridgecrest mainshock. We use the three dimensional finite element method to explore the physical reasons for this curious rupture path. Rather than model the details of the measured and inferred slip distribution, we use simple constant-traction assumptions to explore how initial stress, hypocenter location, and the depth of burial of the initial right-lateral segment may have influenced rupture propagation. The results suggest that only a narrow range of fault stresses, fault burial depths, and hypocenter locations would result in the observed rupture path in this earthquake. The results may have implications for interactions between faults in Southern California and beyond.

Publication Title

Geophysical Research Letters

Recommended Citation

Cortez, J., Oglesby, D., Kyriakopoulos, C., Wu, B., Chaudhuri, K., Ghosh, A., & Douilly, R. (2021). On the Rupture Propagation of the 2019 M6.4 Searles Valley, California, Earthquake, and the Lack of Immediate Triggering of the M7.1 Ridgecrest Earthquake. Geophysical Research Letters, 48 (4) https://doi.org/10.1029/2020GL090659