Mt. Soledad landslide in La Jolla, CA - October 2007

California Geological Survey

California is the most geologically diverse and the second most seismically active state in the USA. The California Geological Survey (CGS) provides scientific products and services about the state's geology, seismology and mineral resources, including their related hazards, that affect the health, safety, and business interests of the people of California. We are one of the oldest geological surveys in the nation, and today produce more products and provide more services to more people than any other state survey. –“A​ltiora Petimus”​ ​(We Reach Higher​​)

 Featured Content



Maps and DataMaps and DataLooking for California geologic maps or GIS data? Start here.
CGS PublicationsCGS PublicationsMaps, reports, data, guidebooks and more are available for download and purchase.
Earthquake Data and ReportsEarthquake Data and ReportsLinks to the Center for Engineering Strong Motion Data, Internet Quick Reports and Internet Data Reports, ShakeMaps, and SMIP Seminar information.
Mineral Resources ProgramMineral Resources ProgramInformation about non-fuel mineral resources, naturally occurring mineral hazards, and active and historic mining activities throughout the state.
EarthquakesEarthquakesRecent and historic earthquakes, faults, earthquake probabilities, earthquake loss estimation, seismic hazard zonation, and more
TsunamisTsunamisGeneral tsunami information, tsunami preparedness, links to tsunami inundation maps, and more





Anniversary of the 1933 Long Beach EarthquakeOn March 10, 1933, a large earthquake tore through the city of Long Beach, prompting the California State Legislature to pass the Field Act., /cgs/Pages/Earthquakes/LongBeach.aspx2019-03-09T08:05:00Z
Scientists on the Front LineCalifornia Geological Survey scientists are part of CAL FIRE-assembled teams that are assessing the potential for flooding and debris flows in areas impacted by recent wildfires. Get the facts on post-fire debris flow, including the difference between mudflows, mudslides, and landslides.,
CGS announces five new Preliminary Seismic Hazard Zone mapsSeismic Hazard Zones are areas that have potential for ground deformation caused by liquefaction or landslides. Areas affected by this release are in Contra Costa and San Mateo counties; click/tap for details. Public comments are due to the State Mining and Geology Board no later than Jan. 2, 2019., /cgs/preliminary-releases2018-10-04T15:00:00Z
CGS Scientists Map Burned AreaOne of the many services provided by the California Geological Survey is post-wildfire assessment of the potential for mudslides. Working with CAL FIRE, CGS sent a crew of geologists to Riverside County to map potential hazards following the recent Holy Fire. CGS post-fire landslide reponse.pdf, CGS post-fire landslide reponse.pdf2018-09-17T19:00:00Z
2018 update to Map Sheet 52 [Aggregate Sustainability in California]Aggregate materials are essential to modern society. Map Sheet 52 summarizes projected aggregate needs and currently permitted reserves., View/download the release statement (PDF document)2018-07-16T07:00:00Z
New Geologic Maps for parts of Humboldt CountyCGS released two new maps for parts of Humboldt County: Landslides, Geomorphology, and Geology of the Owl Creek and Iaqua Buttes 7.5’ Quadrangles, More...2018-07-06T07:00:00Z

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