Landslide Displacement in the San Francisco Bay Region. The HayWired Earthquake Scenario

This map shows the potential of widespread slope failures, in terms of Newmark displacement (measured in centimeters), triggered by a M7.0 scenario earthquake on the Hayward Fault in the 10-county area surrounding the San Francisco Bay region, California. The cumulative downslope displacement of hillslopes is calculated using a simplified Newmark rigid sliding block slope stability model utilizing four primary datasets: a regional-scale geologic map of the study area, geologic strength parameters compiled as part of the California Geological Survey Seismic Hazard Mapping Program, earthquake shaking data from the USGS ShakeMap developed for this scenario, and 10-meter digital elevation data from the USGS 2009 National Elevation Dataset.The seismic-landslide hazard potential 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.

本地图展示了加利福尼亚州旧金山湾区周边10个县范围内，由海沃德断层（Hayward Fault）上发生的M7.0情景地震触发的大范围边坡破坏潜力，其评估指标为纽马克位移（Newmark displacement，单位：厘米）。本研究采用简化版纽马克刚性滑块边坡稳定性模型，计算山坡的累积下坡位移，该模型依托四类核心数据集完成计算：研究区区域地质图、加利福尼亚地质调查局地震危险填图项目编制的地质强度参数、针对本次情景地震开发的美国地质调查局（USGS）震动图（ShakeMap）地震动数据，以及美国地质调查局2009年国家高程数据集（National Elevation Dataset）的10米数字高程数据。该地震滑坡危险潜力地图覆盖的县域包括阿拉米达县、康特拉科斯塔县、马林县、纳帕县、旧金山县、圣马特奥县、圣克拉拉县、圣克鲁斯县、索拉诺县及索诺马县。本次触发边坡破坏的假想地震为矩震级7.0级，于2018年4月18日下午4点18分发生在加利福尼亚州旧金山湾区东湾区域的海沃德断层上。