The Alquist-Priolo Earthquake Fault Zones and fault traces as shown on the Official Alquist-Priolo Earthquake Fault Zones Map of the Santa Clara County. Alquist-Priolo fault zones do not correspond with fault rupture zones. The Alquist-Priolo Earthquake Fault Zoning Act was passed in 1972 to mitigate the hazard of surface faulting to structures for human occupancy. This state law was a direct result of the 1971 San Fernando Earthquake, which was associated with extensive surface fault ruptures that damaged numerous homes, commercial buildings, and other structures. Surface rupture is the most easily avoidable seismic hazard. It directs the State of California Department of Conservation - Geological Survey to compile detailed maps of the surface traces of known active faults. The Alquist-Priolo Earthquake Fault Zoning Act's main purpose is to prevent the construction of buildings used for human occupancy on the surface trace of active faults. The 1:24,000-scale (24K) U.S. Geological Survey (USGS) quadrangle boundary data set contains the approximate boundaries of the various 24K USGS quadrangles and the names and indexing codes associated with each 24K quadrangle. Original Source: : http://www.quake.ca.gov/gmaps/ap/ap_maps.htm.