Asthenosphere: The asthenosphere underlies the lithosphere. The Asthenosphere comprises the upper mantle, where isostatic adjustments are made, and where magma is generated. It is also in this part of the earth, where seismic waves strongly attenuate.
Gravel Blanket in Methane Mitigation A gravel blanket is a 2-inch or 4-inch thick layer of gravel, sand, or approved material that transmits methane soil gas to the horizontal sub-slab perforated pipes and verticle vent riser of a passive methane mitigation system.
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.
Total Petroleum Hydrocarbons (TPH) Total Petroleum Hydrocarbons (TPH): The term “Total Petroleum Hydrocarbons” represents the complete carbon chain of hydrocarbon compounds that originate from petroleum. In general there are three ranges of TPH: Gasoline Range Total Petroleum Hydrocarbons (TPH-g); Diesel Range Total Petroleum Hydrocarbons (TPH-d); and Oil Range Total Petroleum Hydrocarbons (TPH-o). Gasoline range TPH represents the…
Terrestrial Planet Definition A terrestrial planet is any planet in the universe that has earth-like composition, such as rocks, and other similar solid substances. For instance, Mars is a terrestrial planet in our solar system, whereas Jupiter is not. This is because modern geologists, astrophysicists, and astronomers understand Mars to contain solid formations correlative to…
Seismology Seismology: (seis·mol·o·gy) a branch of geology and geophysics that relates to earthquakes, including but not limited to their causes, effects, hazards, and mitigation techniques. Seismologists at the United States Geological Survey (USGS) use cutting-edge technology to measure seismic wave properties and geological hazards that trigger them or are triggered by them. In turn, seismology…
Rock Stratigraphic Unit In the field of geology, a rock stratigraphic unit, or a lithostratigraphic unit, is a geologic formation that is identifiable by a specific lithology, as well as a consistent stratigraphic position. For example, the Monterey Formation is a rock stratigraphic unit, as it tends to consistently comprise the same gravel and sand…
