Hypocentral dependent shallow slip distribution and rupture extents along a strike-slip fault

Abstract

Natural faults feature heterogeneities in geometry, material properties, and stress distributions, posing great challenges in predicting fault slip behaviors. Among these factors, the stress on the fault is poorly understood due to the lack of direct measurements. Here, we estimate stress distribution from interseismic locking models and derive earthquake scenarios along the Anninghe fault in Sichuan, China, by conducting dynamic rupture simulations. The predicted rupture segmentation and moment magnitudes (Mw 6.9 – 7.3) are well consistent with historical earthquakes. Besides, we have observed models accompanied by continuous surface rupture, with surface offsets comparable to the values identified in field surveys of historical earthquakes. In addition, the surface rupture and the shallow slip deficit (SSD) vary drastically among models with different hypocenters, demonstrating that the earthquake process is indeterministic. The coseismic moment predicted in our models is ∼50% of what was anticipated from the static locking model. Our results highlight that those rupture scenarios derived from the locking-based heterogeneous stress can further contribute to the seismic hazard assessment.