A Time Stratigraphic Unit, or a Chronostratigraphic Unit, is a rock unit that is characterized by geological formations, during a specific period of time. This serves as a reference for all rocks formed during the same time period.
Volatile Organic Compounds (VOCs) Volatile Organic Compounds (VOCs): Volatile Organic Compounds are toxic organic chemicals with higher tendencies to change from liquid to vapor phase under typical earth pressures and temperatures, and usually have little-to-no water solubility characteristics. VOCs are commonly found within hydrocarbon-based fuel additives, industrial solvents, refrigerants, hydraulic fluids, degreasers, and more. These…
Seismic Risk Definition Seismic risk is the probability that a subject site will be adversely affected by any seismic hazard, such as an earthquake. Seismic risk tends to increase in areas that are more earthquake-prone and vulnerable to damage. And vulnerability refers to the potential impact on people, as well as properties. For instance, places…
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…
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.
Seiche Definition The term “Seiche” in geology refers to a wave-oscillation, that comes from any surface body of water, that is initiated by an earthquake or changes in atmospheric pressure. For instance, the rippling waters of a lake or at the bay of an ocean.
What is a Concrete Slab and Buttress Dam? A Concrete Slab and Buttress Dam is a freshwater-retaining structure comprising reinforced concrete slabs that are supported in-place by buttresses. The foundation of a Concrete Slab and Buttress Dam receives a large load. Thus, the foundation must be structurally sound, impervious, and competent. The alternative types of dams…
