Landslide Probability in the San Francisco Bay Region. The Haywired Earthquake Scenario

This map shows the potential of widespread slope failures, in terms of landslide probability, triggered by a M7.0 scenario earthquake on the Hayward Fault in the 10-county area surrounding the San Francisco Bay region, California. The likelihood of landsliding was evaluated using an equation developed by Jibson and others (2000) that estimates landslide probability as a function of predicted Newmark displacement. Based on this equation, four landslide probability categories are established with their corresponding percent likelihood and displacement ranges: Low (0-2%; 0-1 cm), Moderate (2-15%; 1-5 cm), High (15-32%; 5-15 cm), and Very High (>32%; >15 cm).The seismic-landslide probability map covers the counties of Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Santa Cruz, Solano, and Sonoma. The slope failures are triggered by a hypothetical earthquake with a moment magnitude of 7.0 occurring on April 18, 2018, at 4:18 p.m. on the Hayward Fault in the east bay part of California’s San Francisco Bay region.