Data · dataset · 2026
Map Sheet 48 (2025 update) - MMI from PGA (10% in 50 years)
Listed in California Open Data
The California Geological Survey (CGS) Map Sheet 48 (MS48) provides a depiction of expected ground shaking intensity from future earthquakes across the state.
Description
The shaking intensity is represented using the Modified Mercalli Intensity (MMI) scale, which describes the perceived earthquake shaking and correlates strongly with earthquake-induced damage. MS48 maps the level of shaking with a 2% probability of being exceeded in 50 years, equivalent to a 2,475-year average recurrence interval.
In addition to MS48, eight interactive MMI hazard maps are presented. These include MMIs calculated using alternative methods. For each method, MMIs 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).
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The Arc GIS interface allows users to select any two MMI hazard maps to compare side by side. MMI values were calculated using several ground motion to intensity conversion equations (GMICEs). 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 MMI application , use the following configuration: Number of Classes: 7 Classes & Hex Codes: 4 - 5: #ffffbf 5 - 6: #f5f500 6 - 7: #f7ce00 7 - 8: #fa7d00 8 - 9: #fd2a00 9 - 10: #c70808 10 - 11: #8c0808
Links
Get the data
- Publisher page gis-cnra.hub.arcgis.com/datasets/cadoc::map-sheet-48-2025-update-mmi-from-pga-10-in-50… ↗
documentation · download · from data ca gov
- ArcGIS GeoService gis.conservation.ca.gov/server/rest/services/CGS/MS48_MMI_PGA_10pc50/ImageServer ↗
download · from data ca gov
Where it is published
- California Open Data dataset page data.ca.gov/dataset/map-sheet-48-2025-update-mmi-from-pga-10-in-50-years ↗
landing page · from data ca gov
Catalogue records · 1
- CKAN API data.ca.gov/api/3/action/package_show?id=0ded2b6c-06ab-4fe5-874d-90df22717… ↗
metadata API · from data ca gov
Topics
- Stated by source
- Natural Resources
- From keywords
- Earth & Environmental Science
Provenance · 1 source records, 9 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| California Open Data | 0ded2b6c-06ab-4fe5-874d-90df227171fd | 9 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · data ca gov | connector:data_ca_gov@1.0.0 | |
| concepts[field].local:field:earth-environmental | mapping · data ca gov | connector:data_ca_gov@1.0.0 | |
| concepts[topic].ckan_group:data_ca_gov:natural-resources | source · data ca gov | connector:data_ca_gov@1.0.0 | |
| created_date | source · data ca gov | connector:data_ca_gov@1.0.0 | |
| description | source · data ca gov | connector:data_ca_gov@1.0.0 | /notes |
| license_text | source · data ca gov | connector:data_ca_gov@1.0.0 | |
| publication_date | source · data ca gov | connector:data_ca_gov@1.0.0 | |
| title | source · data ca gov | connector:data_ca_gov@1.0.0 | /title |
| updated_date | source · data ca gov | connector:data_ca_gov@1.0.0 |