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.
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.

Epicenter Epicenter: In the seismology branch of geology, an epicenter of an earthquake is the point on Earth’s surface that is directly above the focus (or hypocenter). It is the ground surface location overlying where an earthquake rupture originates within a dip-slip fault or strike-slip fault. Shortly after an earthquake, United States Geological Survey (USGS)…

Environmental Geology Environmental Geology: (en·vi·ron·men·tal ge·ol·o·gy) a branch of geology that relates to the impact of human activity on Earth, and the pollution of geologic formations, reserves, and resources. Common focus points of environmental geology are contaminated soil, groundwater aquifers, lakes, rivers, and the ocean. Professional geologists assess and remediate contamination plumes in all media,…

Unobstructed Opening Definition in Methane Mitigation Unobstructed Opening: Per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, an unobstructed opening is a permanent clearance or gap in the walls, floors, or ceiling of a structure, to allow for direct fresh airflow. In methane mitigation plan applications, this does not…

Runoff (R) The term “Runoff” (R) in hydrogeology and geology refers to the part of rainfall which accumulates on the ground surface and naturally forms into flowing streams.

Anion Anion: In the fields of chemistry and geochemistry, an anion is a negatively charged ion. The oppositely charged ion is a cation.

Liquefaction Liquefaction: Liquefaction is the process by which there is: (1) a sudden and significant decrease of shear resistance in a soil sample (cohesion-less); (2) a sudden (but temporary) increase of the pore-water pressure of a substance; and (3) a solid mass of soil that is transformed into a fluid state mass. In the event…