Dynamic stress perturbation on the M7.1 Ridgecrest earthquake fault from the preceding M6.4 event: a theoretical study with dynamic rupture models

Baoning Wu, David D. Oglesby, Jordan Cortez, & Christodoulos Kyriakopoulos

Published August 15, 2019, SCEC Contribution #9788, 2019 SCEC Annual Meeting Poster #280

The 2019 Ridgecrest earthquake sequence included a M6.4 event and a M7.1 event occuring 33 hours apart, rupturing two perpendicular faults. Questions arise about how much the M6.4 event contributed to the M7.1 rupture. While the detailed rupture history of the M6.4 event is not available to us, we investigate some possible scenarios with dynamic rupture models to evaluate the time-dependent stress perturbation on the M7.1 event fault generated by the M6.4 event. We model the M6.4 event with a 3D finite element code FaultMod (Barall, 2009), incorporating mapped fault geometry. Only the NE-SW trending M6.4 event fault is allowed to slip, while the NW-SE M7.1 event fault is forced not to slip so that the 1-way interaction between the 2 events can be studied. Our preliminary results highlight two potential factors that could strongly affect the time-dependent stress field on the M7.1 fault: 1. how far the M6.4 rupture penetrated across the M7.1 fault, and 2. the rupture directivity (nucleation location) of the M6.4 event.

Key Words
dynamic stress perturbation, Ridgecrest earthquake, dynamic rupture model

Citation
Wu, B., Oglesby, D. D., Cortez, J., & Kyriakopoulos, C. (2019, 08). Dynamic stress perturbation on the M7.1 Ridgecrest earthquake fault from the preceding M6.4 event: a theoretical study with dynamic rupture models. Poster Presentation at 2019 SCEC Annual Meeting.

Related Projects & Working Groups
Ridgecrest Earthquakes