
The intent of the Alquist-Priolo Act is to prohibit the location of developments and structures for human occupancy across the trace of active fault, thus avoiding the hazard of surface fault rupture.
​
Earthquake Fault Zones encompass hazardous faults, which are defined as those faults that are sufficiently active and well-defined:
​
* Sufficiently active - faults that exhibit evidence of Holocene displacement
(approximately last 11,000 years)
​
* Well-defined - trace detectable by trained geologist


NOAA Natural Hazards Image Database
1906 San Fransisco Earthquake. M = 8.2
1979 El Centro Earthquake. M = 6.9
1971 San Fernando Earthquake. M = 6.6
NOAA Natural Hazards Image Database
Youd, T.L & Olsen H.W in Geological Survey Professional Paper 733