ABAG Fault Rupture Hazard Information

 
Hayward Fault Trace Information
Interactive (Google Earth) Hayward Fault Map - (RELEASED MARCH 2006 - courtesy of the U.S. Geological Survey)
Tour the Hayward Fault - Have you ever wondered what a fault looks like? During May and June 2006, you can see one - underground - at Fremont's Central Park
Alquist-Priolo Earthquake Fault Study Zone Information
Earthquakes occur in the Bay Area when forces underground cause the faults beneath us to rupture and suddenly slip. If the rupture extends to the surface, we see movement on a fault (surface rupture). Because faults are weaknesses in the rock, earthquakes tend to occur over and over on these same faults. The California Geological Survey publishes maps of the active faults in the Bay Area that reach the surface as part of its work to implement the requirements of the Alquist-Priolo Earthquake Fault Zone Act. These maps show not only the most comprehensive depiction of fault traces that can rupture the surface, but also the zones in which cities and counties must require special geologic studies to prevent the building of structures intended for human occupancy from being built and in which the surface rupture hazard must be disclosed in real estate transactions. Note, however, that strong earthquakes can occur when the fault rupture does not extend to the surface, and that fault-related damage is rare when compared to shaking-related damage.
Interactive (GIS) Alquist-Priolo Earthquake Fault Zone Maps - "Zoom in" capability! (suitable for DSL, cable modem, and other fast connections)
 

This interactive map was reproduced with permission, California Geological Survey from CD-ROM 2001-04 (2001), Official Map of Alquist-Priolo Earthquake Fault Zones (AP EFZ).

It was created using digital files of AP EFZ quadrangles and is considered an electronic facsimile of the Official Alquist-Priolo Earthquake Fault Zone map. If there is any doubt or conflict with respect to the location of EFZ boundaries, the original clear-film
overlay compiled by and on file with CGS is the official version of the map. Fault information in these digital files is not sufficient to serve as a substitute for the geological site studies required under Chapter 7.5 of Division 2 of the California Public Resources Code.

More Information from the California Geological Survey
ABAG, the Association of Bay Area Governments, is the regional planning and services agency for the nine-county San Francisco Bay Area.

This page was last updated 5/9/06 by jpb.