Map Sheet 48 (2025 update) - Ground Motion from PGV (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: Inferno Minimum: 6.8 cm/s Maximum: 269 cm/s Gamma: 1

本影像服务为加州地震灾害可视化专题地图集的组成部分，涵盖PGA、PGV以及周期为0.2秒（SA02）、1.0秒（SA10）、2.0秒（SA20）的谱加速度相关专题地图。针对每一类地震动参数，本影像服务提供两种不同超越概率水准的灾害分布图：其一为50年超越概率2%（对应重现期约2475年），其二为50年超越概率10%（对应重现期约475年）。ArcGIS Online 界面支持用户任选两幅地震动灾害地图进行并排对比。本次地震动参数的计算基于美国地质调查局2023年更新版全国地震灾害模型。详细信息请参阅MS48网页的"科学背景"栏目。受软件功能限制，本影像服务暂不支持添加符号系统。若需匹配MS48地震动应用程序所用的符号系统，请采用如下配置：Esri 色彩渐变方案：Inferno；最小值：6.8 cm/s；最大值：269 cm/s；伽马值：1。