Topple Definition
Topple – Slope movement due to forces that cause an overturning moment about a pivot point below the center of gravity of the unit.
Topple – Slope movement due to forces that cause an overturning moment about a pivot point below the center of gravity of the unit.

Vapor Intrusion Vapor Intrusion occurs when harmful soil contamination changes phase from liquid to vapor underground and moves upward through geologic layers and building foundations, accumulating within indoor air.

Mechanical Extraction System Mechanical Extraction System: Per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a Mechanical Extraction System is one of the Active Methane Mitigation criteria for methane mitigation systems in buffer zones and methane zones. A mechanical extraction system uses machines that remove methane gas from below…

Mineral Definition A mineral is defined as an inorganic element, compound, or substance that naturally develops with an organized internal structure and/or crystal form over time. Minerals are also distinguishable by their chemical composition and physical properties, as determined in laboratories by geologists. Typical earth minerals found in most igneous, metamorphic, and sedimentary rocks are…

Seismic Moment Seismic Moment: In the seismology branch of geology, seismic moment represents a measure of the size of an earthquake, depending on the area of rupture, the rigidity of the rock, and the amount of slip from faulting.

Thermosphere Thermosphere: The thermosphere of a terrestrial planet is the fourth and final member of the atmosphere. On Earth, the thermosphere starts atop the mesosphere at approximately 85 kilometers above mean sea level. The upper limit of the thermosphere is reasonably presumed to terminate approximately 95 kilometers above mean sea level. In fact, most of…

Ultramafic Definition In the study of geology, the term “ultramafic” refers to an igneous rock that comprises up to 90% mafic minerals, or more.