Fault Activity Map of California (2010)

The map shows locations of known faults that can be portrayed at 1:750,000 scale and indicates the latest age when displacements took place, according to available data. The displacements may have been associated with earthquakes or may have been the result of gradual creep along the fault surface.

The faults are separated into five categories: historic, Holocene, late Quaternary, Quaternary, and pre-Quaternary. The 2010 Fault Activity Map of California presents a much more detailed depiction of faults in California than previous versions. In order to preserve as much of the original detail as possible, most faults active in the Quaternary (2.6 Ma) were digitized from their original sources (geologic maps ranging from 1:12,000 to 1:250,000 scale).