A probabilistic displacement hazard assessment framework for coseismic distributed fracturing from strike-slip earthquakes

Alba M. Rodriguez Padilla, & Michael E. Oskin

In Preparation May 31, 2022, SCEC Contribution #11869

Widespread distributed fracturing during earthquakes threatens infrastructure and lifelines. We combine high-resolution surface rupture maps from the four major surface-rupturing strike-slip earthquakes in southern California and northern Mexico since 1990 to incorporate the displacements produced by secondary faulting and fracturing into a probabilistic displacement hazard analysis framework. Through analysis of the length and density distribution of mapped fractures for each event, we develop an expression for the probability of finding a fracture at a given distance away from the fault that accommodates a displacement that exceeds a given threshold Do. In our model, Do is a user-input variable that may be adjusted for different engineering applications. To facilitate general use, we also recast this relationship in terms of earthquake magnitude. Our proposed model may be used to simulate the expected secondary displacements for strike-slip earthquakes with widespread fracturing across immature fault zones, such as the Eastern California Shear Zone or the Walker Lane Belt of California and Nevada, USA.

Citation
Rodriguez Padilla, A. M., & Oskin, M. E. (2022). A probabilistic displacement hazard assessment framework for coseismic distributed fracturing from strike-slip earthquakes. Seismological Research Letters, (in preparation).