Body-Wave Magnitude
Body-Wave Magnitude: A method for determining earthquake size from the amplitude of body waves. The body-wave magnitude focuses on P-waves and S-waves, which travel faster through the Earth’s crust and mantle.
Body-Wave Magnitude: A method for determining earthquake size from the amplitude of body waves. The body-wave magnitude focuses on P-waves and S-waves, which travel faster through the Earth’s crust and mantle.

Index Fossil Definition An Index fossil, in the field of paleontology, refers to a fossil that identifies and dates the stratigraphic unit that it is observed to exist in. Index fossils can combine a wide geographic range. And they can really narrow down the classifications of most stratigraphic units.

Transgression Transgression: In geology, the term transgression is the formation of a specific sequence of sedimentary and metamorphic layers, that are the result of ocean water advancing onto land. To illustrate, when transgression occurs over millions of years, geologists find a layer of sand, overlain by shale, and overlain again by limestone. The opposite of…

Methane Soil Gas Methane Soil Gas: In geology, methane soil gas refers to the confinement of CH4 within the interstitial pore spaces of subsurface soils. On Earth and potentially on Mars, methane derives from subsurface pockets of biogenic and petrogenic natural gas. To illustrate, accumulations of buried organic matter decay via microbial or thermal degradation….

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.

Polychlorinated Biphenyl (PCBs) Polychlorinated Biphenyl (PCBs): Polychlorinated Biphenyl (PCBs) are highly toxic human-engineered chlorinated hydrocarbons that have been used around the world as enhancers to hydraulic oil and electrical insulators. PCBs were applied for maintaining low flammability rates, high boiling points, and stronger chemical stability. As of 1979, PCBs have been banned from use in…

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