San Francisco Bay Region Geology and Geologic Hazards
About Quaternary Faults > How Was the Map of Quaternary-Active Faults Made?
How Was the Map of Quaternary-Active Faults Made?
This map was produced as a collaborative effort of the USGS, California Geological Survey, and geologists in the academic and private sectors, using a variety of mapping techniques, including LIDAR, interpretation of aerial photographs, and on-the-ground mapping of faults.
The map was compiled from three sources. The first was detailed new mapping of faults throughout the region. These contributions are listed below:
The second source was the map of Quaternary-active faults of California, prepared by B. Bryant, CGS, for the National Quaternary Fault Map Database.
The third source was the geologic map of the San Francisco Bay region.