Map Sheet 48 (2025 update) - Ground Motion from PGA (10% in 50 years)

This image service is part of a collection of maps for PGA, PGV and spectral accelerations at 0.2 s (SA02), 1.0 s (SA10), and 2.0 s (SA20) to illustrate seismic hazards in California. For each ground motion parameter, maps at two different hazard levels were presented: one with a 2% probability of being exceeded in 50 years (equivalent to 2,475-year recurrence interval) and the other with 10% probability of being exceeded in 50 years (equivalent to 475-year recurrence interval). The ArcGIS Online interface allows users to select any two ground motion hazard maps to compare side by side. Ground motion parameters were calculated using the 2023 update of the U.S. Geological Survey National Seismic Hazard Model. See the “Scientific Background” on MS48 webpage for detailed information. Due to software limitations, symbology cannot be added to this service. To match the symbology used in the MS48 Ground Motion application, use the following configuration: Esri Color Ramp: Magma Minimum: 4.41 g Maximum: 0.032 g Gamma: 1本影像服务为展示加利福尼亚州地震灾害的地图集的组成部分，该图集涵盖峰值地面加速度（Peak Ground Acceleration, PGA）、峰值地面速度（Peak Ground Velocity, PGV），以及0.2秒（SA02）、1.0秒（SA10）、2.0秒（SA20）对应的谱加速度地图。针对每一类地震动参数，本图集提供了两种不同灾害水准的地图：其一为50年内超越概率2%（对应重现期2475年）的成果，其二为50年内超越概率10%（对应重现期475年）的成果。ArcGIS Online（ArcGIS在线）平台支持用户任选两张地震动灾害地图进行并排对比。本次地震动参数的计算采用了美国地质调查局（U.S. Geological Survey, USGS）2023年更新版的全国地震灾害模型。详细信息请参阅MS48网页上的"Scientific Background"板块。受软件限制，本服务无法添加地图符号系统。若需匹配MS48地震动应用中所使用的符号系统，请采用如下配置：Esri色彩渐变（Esri Color Ramp）：Magma；最小值：4.41 g；最大值：0.032 g；伽马值（Gamma）：1