Surface-Wave Magnitude “Surface-Wave Magnitude” is the magnitude of an earthquake that scientists estimate using measurements of the amplitude of surface waves.

Milliequivalent per liter Milliequivalent per liter (meq/L): A unit used to express the chemical equivalence of the concentration of solutes in a solution. It is calculated by dividing the concentration of a substance (in mg/L) by its equivalent weight. This measurement helps in understanding the reactive capacity of ions in the solution.

Troposphere Troposphere: The troposphere of a terrestrial planet is the lowest member of the atmosphere. On Earth, the troposphere starts atop the ground surface and terminates roughly 10 kilometers above mean sea level. In fact, geologists understand that most of the Earth’s water vapor (clouds) exists in the troposphere. And the next member of the…

Trench Dam Trench Dam: Per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a trench dam is part of a methane mitigation system. A trench dam is essentially a subsurface barrier that exists within a furrow or ditch, that is adjacent to the foundation of a building in a…

Rigidity Definition Rigidity – In geotechnical engineering and engineering geology, rigidity represents the ratio of the shear stress and the amount of angular rotation that it produces, within a rock sample.

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…