Simulations of localization process leading to large earthquakes

xiaoyu zhou, Jessica A. McBeck, Francois Renard, & Yehuda Ben-Zion

Submitted September 11, 2022, SCEC Contribution #12411, 2022 SCEC Annual Meeting Poster #156

Recent work shows that large events (M>7) such as the Landers 1992 and Ridgecrest 2019 earthquakes in Southern California were preceded by localization of low magnitude background seismicity around their eventual rupture zones (Ben-Zion & Zaliapin 2019, 2020). To help refine target signals and understand the controlling factors of localization processes in brittle rock, we build discrete element models (DEM) with a rough fault zone embedded in a damage zone and host rock using ESyS-Particle. We use models with varying fault/off-fault parameters including cohesion, Young’s modulus, fault zone width, and different confining stress to examine their influence on fracture network localization. We convert fractures (e.g., broken bonds) into deviatoric seismic potency using the formulation of Ben-Zion & Lyakhovsky (2019). We then track localization using the cumulative potency and cumulative differential motion across the fault zone. The observed relationship between various fault zone/host rock parameters and localization behavior of fractures may improve the ability to track preparation processes that lead to large earthquakes.

Citation
zhou, x., McBeck, J. A., Renard, F., & Ben-Zion, Y. (2022, 09). Simulations of localization process leading to large earthquakes. Poster Presentation at 2022 SCEC Annual Meeting.

Related Projects & Working Groups
Fault and Rupture Mechanics (FARM)