Map Sheet 48 (2025 update) - Site Condition

This map shows distribution of the time-averaged shear-wave velocity in the upper 30 m (Vs30) for California. Vs30 is used as a proxy for local geologic site condition in ground motion hazard calculations. The map is produced using data provided by Thompson (ver. 2.0, July 2022), which is based on the method described by Thompson and others (2014) with adjustments (see Thompson, 2022 for detail). Vs30 unit is m/s. Data resolution is 3 arcseconds (approximately 90 m). Due to software limitations, symbology cannot be added to this service. To match the symbology used in the MS48 Additional Maps application, use the following configuration: Esri Color Ramp: Yellow to Dark Red Number of Classes: 5 Classes & Hex Codes: 176.1 - 300: #F4FE93 300 - 450: #F6DC6A 450 - 600: #F2B841 600 - 725: #BA671A 725 - 1,473.3: #810A01本地图展示了加利福尼亚州浅层30米内时均剪切波速（Vs30）的空间分布。Vs30在地震动危险性计算中被用作局部地质场地条件的代理指标。本地图基于Thompson（2022年7月，版本2.0）提供的数据制作，其方法源自Thompson等人2014年提出的研究方案并经调整（详细信息参见Thompson, 2022）。Vs30的单位为米每秒（m/s）。数据分辨率为3角秒（约合90米）。受软件限制，本服务无法添加符号化图层。若需匹配MS48附加地图应用中所使用的符号体系，请采用以下配置：Esri色阶（Esri Color Ramp）：黄色至暗红色；分类数量：5类；分类区间与十六进制颜色代码分别为：176.1~300：#F4FE93，300~450：#F6DC6A，450~600：#F2B841，600~725：#BA671A，725~1473.3：#810A01。