Thrust Fault Thrust Fault: In the field of geology, a thrust fault is a reverse fault in which the fault plane dipping angle is less than 45 degrees. Thrust faults are dip-slip faults, and can also be listric faults. For instance, the fault underlying the western embankment of the historical St. Francis Dam in Saugus,…

Lithosphere Lithosphere: The lithosphere comprises the Earth’s crust as well as part of the upper mantle. In fact, the lithosphere is approximately 100 kilometers thick and is relatively strong as compared to the underlying asthenosphere.

Wing Dam or Wing Dike A “Wing Dam” or “Wing Dike” refers to a dam that intentionally retains a fraction of the width of a flowing water source. Unlike a conventional dam, a wind dam aims to divert the path of water flow. Additionally, a wing dike can control the velocity of water flow. For…

De-Watering System in Methane Mitigation De-Watering: In accordance with the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a de-watering system is a permanent water removal system in a methane mitigation system. In the mitigation process, a de-watering system consists of perforated horizontal pipes, gravel pockets, sump areas with pumps,…

Petrogenic Gas Petrogenic Gas: In geology, petrogenic gas refers to natural gas that is the byproduct of the thermal decomposition of biological and organic matter. In fact, this is the same process that results in the geological formation of petroleum underground. For instance, methane soil gas hazards in Los Angeles Methane Zones are typically resulting…