Map Sheet 48 (2025 update) - Ground Motion from SA02 (2% 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

本影像服务为加州地震灾害可视化地图集的组成部分，涵盖PGA、PGV以及周期0.2秒（SA02）、1.0秒（SA10）与2.0秒（SA20）的谱加速度数据。针对每一类地震动参数，本数据集提供两种不同地震危险性水准的地图：其一为50年超越概率2%（对应重现期2475年），其二为50年超越概率10%（对应重现期475年）。ArcGIS Online（ArcGIS在线平台）界面支持用户任选两张地震动危险性地图进行并排对比。本次地震动参数基于美国地质调查局（U.S. Geological Survey，USGS）2023年更新版全国地震危险性模型计算得到。详细信息请参阅MS48网页中的"科学背景"板块。受软件限制，本服务暂无法设置符号系统。若需匹配MS48地震动应用中所使用的符号化样式，请采用如下配置：Esri色阶（Color Ramp）：Magma；最小值：4.41 g；最大值：0.032 g；伽马值（Gamma）：1。