{ "culture": "en-US", "name": "MS48_Vs30_ShearWaveVelocity2022", "guid": "", "catalogPath": "", "snippet": "Depicting distribution of Vs30 values in California which affects the distribution of MMI and ground motion hazards. For example, sedimentary basins (low Vs30 values) generally experience amplified shaking.", "description": "
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).<\/div>

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Due to software limitations, symbology cannot be added to this service. To match the symbology used in the <\/font>MS48 Additional Maps application<\/a>, use the following configuration: <\/font><\/i><\/div>
  • Esri Color Ramp: Yellow to Dark Red<\/i><\/font><\/li>
  • Number of Classes: 5<\/i><\/font><\/li>
  • Classes & Hex Codes:<\/i><\/font><\/li>
  • 176.1 - 300: #F4FE93<\/i><\/font><\/li>
  • 300 - 450: #F6DC6A<\/i><\/font><\/li>
  • 450 - 600: #F2B841<\/i><\/font><\/li>
  • 600 - 725: #BA671A<\/i><\/font><\/li>
  • 725 - 1,473.3: #810A01<\/i><\/font><\/li><\/ul><\/div>

    <\/div><\/div>", "summary": "Depicting distribution of Vs30 values in California which affects the distribution of MMI and ground motion hazards. For example, sedimentary basins (low Vs30 values) generally experience amplified shaking.", "title": "Map Sheet 48 (2025 update) - Site Condition", "tags": [ "MS48", "Map Sheet 48", "California Geological Survey", "CGS", "Earthquake Shaking Potential", "California Department of Conservation", "California Natural Resources Agency", "CAOpenData" ], "type": "Image Service", "typeKeywords": [ "ArcGIS Server", "Data", "Image Service", "Service" ], "thumbnail": "", "url": "https://gis.conservation.ca.gov/server", "minScale": 1.8489297737240918E7, "maxScale": 288895.27714438934, "spatialReference": "GCS_WGS_1984", "accessInformation": "Thompson, E.M., 2018, An Updated Vs30 Map for California with Geologic and Topographic Constraints (ver. 2.0, July 2022): U.S. Geological Survey data release, https://doi.org/10.5066/F7JQ108S.", "licenseInfo": "
    Access Constraints: Because digital data are easily altered, cities, counties, and others who use this are advised to obtain the file directly from the Department of Conservation, California Geological Survey.<\/div>" }