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

  • Volatile Organic Compounds (VOCs)

    Volatile Organic Compounds (VOCs) Volatile Organic Compounds (VOCs): Volatile Organic Compounds are toxic organic chemicals with higher tendencies to change from liquid to vapor phase under typical earth pressures and temperatures, and usually have little-to-no water solubility characteristics. VOCs are commonly found within hydrocarbon-based fuel additives, industrial solvents, refrigerants, hydraulic fluids, degreasers, and more. These…

  • Porosity (n)

    Porosity (n) “Porosity” (n), in the geological engineering field, is a percentage value that represents the bulk volume of a rock or soil, that is occupied by the void space within. Porosity (n) Formula Porosity (n) = [(Volume of Voids ÷ Total Volume) x 100%]

  • Permeability

    Permeability “Permeability” in engineering geology and geotechnical engineering refers to the property of a soil sample (or porous rock) which relates to transmitting a fluid within. Permeability measures the relative case of flow under unequal pressure. Permeability is calculated using Darcy’s Law.

  • Well Graded

    Well Graded Soil Well Graded: In the soil classification process of geology, well graded soil represents a sedimentary soil sample that fully displays all of the possible grain sizes for that soil classification, in accordance with the Unified Soil Classification System (USCS). For example, a well graded sand (SW) comprises fine, medium, and coarse grains…

  • Design Methane Concentration

    Design Methane Concentration Design Methane Concentration: In accordance with the Los Angeles Department of Building and Safety Methane Code, Ordinance Number 175790, a Design Methane Concentration is the highest recorded concentration of methane soil gas detected during the course of methane testing on a property. The Design Methane Concentration is what defines the level of…

  • Facies

    Facies Facies: In the field of geology, the term “facies” represents a mappable, areally restricted part of a rock body that has different fossils or lithology from other contiguous beds deposited at the same time.