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…

Methane Mitigation Soil Gas Pressure Sensor Methane Mitigation Soil Gas Pressure Sensor: A Methane Mitigation Soil Gas Pressure Sensor is a device that measures and communicates sub-slab soil gas pressure to a methane control panel system. High levels of methane soil gas then trigger the integrated methane alarm system to notify occupants of danger. Much…

Critical Void Ratio The “Critical Void Ratio,” in soil science and geology, represents the final void ratio of a soil sample, at ultimate strength. And Critical Void Ratio is achieved by the loose and dense samples of the same soil post-shearing.

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.

Total Petroleum Hydrocarbons (TPH) Total Petroleum Hydrocarbons (TPH): The term “Total Petroleum Hydrocarbons” represents the complete carbon chain of hydrocarbon compounds that originate from petroleum. In general there are three ranges of TPH: Gasoline Range Total Petroleum Hydrocarbons (TPH-g); Diesel Range Total Petroleum Hydrocarbons (TPH-d); and Oil Range Total Petroleum Hydrocarbons (TPH-o). Gasoline range TPH represents the…

Triggered Creep In the field of geology, the term “Triggered Creep” refers to a type of creeping landslide, usually along a fault line, that is triggered by a source of seismic activity.