Alquist-Priolo Earthquake Fault Zoning Act

Alquist-Priolo Earthquake Fault Zoning Act

Alquist-Priolo Earthquake Fault Zoning Act: The Alquist-Priolo Earthquake Fault Zoning Act is a law that assists geologists to define “active faults” versus “potentially active faults.” The process entails using the same aging criteria as the United States Geological Survey (USGS) and the California Geological Survey (CGS). In fact, California policy requires zoning any potentially active fault that possesses a relatively high potential for ground rupture, for future public reference. The law was originally passed in 1972 as the “Alquist-Priolo Special Studies Zones Act.” Currently, it has undergone some reform, and is now referred to as the “Alquist-Priolo Earthquake Fault Zoning Act.”

The Alquist-Priolo Earthquake Fault Zoning Act commonly applies to the seismology, engineering geology, and geotechnical branches of geology.

Fault Investigations

As per the CGS, strike-slip faults and dip-slip faults may be categorized as “active,” “potentially active,” or “inactive.” Active faults show displacement within the past 11,000 years. Potentially active faults show displacement within the last 1.6 million years. And inactive faults show no evidence of displacement within the last 1.6 million years.

Similar Posts

  • Well Log

    Well Log (Boring Log) Well Log: A geological well log (or boring log) is a detailed record of subsurface materials encountered during a drilling project. Boring logs, or well logs, are written by a geologist, and describe the physical subsurface characteristics and lithological units encountered during well-plotting. Well logs include information about depth, different formations,…

  • Transmissivity

    Transmissivity Transmissivity: In geology and hydrogeology, transmissivity (T) represents the capacity of an aquifer to transmit water of the prevailing kinematic viscosity. Formula T=Kb, where b = saturated thickness of the aquifer. Dimensions are gallons per day per foot (gpd/ft) or feet squared per day (ft^2/day).

  • Confined Aquifer

    Confined Aquifer Confined Aquifer: In the hydrogeology branch of geology, a confined aquifer is an aquifer that is overlain (and underlain) by a layer of low permeability, such as clay, shale, or silty clay. In fact, the two confining layers contain the storage and flow of groundwater, such that the aquifer maintains hydraulic pressure (or…

  • Fault Scarp

    Fault Scarp Fault Scarp: In the field of geology, a dip-slip fault scarp is a steep slope that is formed directly by fault movement. It occurs along the line of a normal fault, reverse fault, or transform fault. A fault scarp represents the planer surface of the fault before erosion and weathering modify it.