Gallium (Ga)A chemical element, metallic in nature, used in making certain kinds of solar cells and semiconductor devices.
gapA missing section on one of the strands of double-stranded DNA. The DNA will therefore have a single-stranded region.
GDAsSee Renewable Resource Generation Development Areas
Generalist (species)An organism that can survive under a wide variety of conditions, and does not specialize to live under any particular set of circumstances.
GeoglyphsGround markings of a figure or shape produced by the clearing or alignment of stones.
Geographic air basin: A land area with generally similar meteorological and geographic conditions throughout.
Geographic Information System (GIS)A set of computer tools and procedures used to collect, manage, analyze and display information associated with a specific location; a computerized…
GeologyThe science that deals with the study of the materials, processes, environments, and history of the Earth, including the rocks and their formation and…
Geometric spreadingAs the sound moves away from the source, the area that the sound energy covers becomes larger and thus sound intensity decreases.
GeotechnicalRefers to the use of scientific methods and engineering principles to acquire, interpret, and apply knowledge of earth materials for solving engineering…
Geotextile matsPermeable fabrics that interact with soils in manners used to reinforce soil surfaces for erosion, as well as act as filters for water, solutes, and fine…
Geothermal energyEnergy produced by the internal heat of the earth; geothermal heat sources include: hydrothermal convective systems; pressurized water reservoirs; hot dry…
Geothermal generating plantA plant in which the prime mover is a steam turbine. The turbine is driven either by steam produced from hot water or by natural steam that derives its…
Geothermal resourcesTypically underground reservoirs of hot water or steam created by heat from the Earth, but also include subsurface areas of dry hot rock.
Glacial tillAn unsorted, unstratified mixture of fine and coarse rock debris deposited by a glacier.
GlareThe excessive brightness from a direct light source that makes it difficult to see what one wishes to see.
GlintA momentary flash of light resulting from a spatially localized reflection of sunlight. See also Glare
Global WarmingA popular term used to describe the increase in average global temperatures due to the greenhouse effect.
Graben (fault-bounded basins)An elongated crustal block that is relatively depressed (down dropped) between two parallel normal faults or horsts. See also Half-graben
Graminoid herbaceousA grass or plant of similar growth form, such as sedges, rushes, and others.
Grandfathered rightsIn Arizona, grandfathered water rights are based on historic use of groundwater for five years prior to the designation of an Active Management Area.
GraniteA coarse-grained felsic intrusive (or plutonic) igneous rock with at least 65% silica.
GranodioritesA plutonic igneous rock, formed by an intrusion of silica-rich magma, which cools in batholiths or stocks below the Earth's surface.
GrasslandsGrasslands are characterized as lands dominated by grasses rather than large shrubs or trees.
GraverA small tool with a sharp tip that was used to engrave bone, stone, wood, or other materials.
GrazingConsumption of native forage from rangelands or pastures by livestock or wildlife.
Grazing allotmentAn area where one or more livestock operators graze their livestock. An allotment generally consists of federal land but may include parcels of private or…
Grazing leaseAn authorization that permits the grazing of livestock on public lands outside the grazing districts during a specified period of time (Section 15 of the…
Great BasinAn area covering most of Nevada and much of western Utah, as well as portions of southern Oregon and southeastern California, consisting primarily of…
Greenhouse gase (GHG)Heat-trapping gases that cause global warming. Natural and human-made greenhouse gases include water vapor, carbon dioxide, methane, nitrogen oxides…
GridA common term referring to an electricity transmission and distribution system.
GroundA device used to protect the user of any electrical system or appliance from shock.
Ground failurePermanent ground displacement capable of damaging structures that may occur as a result of differential settlement, liquefaction, lateral spreading, or…
Ground fault matsMats made of insulating materials that do not conduct electricity.
Ground motion (shaking)The movement of the Earth's surface from earthquakes. Ground motion is produced by seismic waves that are generated by a sudden slip on a fault and travel…
GroundwaterAll water below the surface of the land. It is water found in the pore spaces of bedrock or soil, and it reaches the land surface through springs or it…
Groundwater basin: (1) A general term used to define a groundwater flow system that has defined boundaries and may include permeable materials that are capable of storing…
Groundwater overdraftThe condition in which water extractions from an aquifer exceed recharge processes in such excess as to cause substantial and sustained decreases in…
Groundwater rechargeInflow of water to a ground-water reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural…