Poster Presentation

Widespread distributed fracturing during earthquakes threatens infrastructure and lifelines. We combine high-resolution rupture maps from the four major surface-rupturing strike-slip earthquakes in southern California and northern Mexico since 1992 to incorporate the displacements produced by secondary faulting and fracturing into a probabilistic displacement hazard analysis framework. Through analysis of the length and spatial distribution of mapped fractures for each event, we develop an expression for the probability of finding a fracture that accommodates a displacement that exceeds a given threshold Do at a given distance away from the fault. In our model, Do is a user-input variable that may be adjusted for different engineering applications. Our model is best applied to estimating 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.