Degassing - Degassing, also known as degasification, is the removal of dissolved gases from liquids, especially water or aqueous solutions. Angle of Repose - The angle of repose, or critical angle of repose,[1] of a granular material is the steepest angle of descent or dip relative to the horizontal plane on which the material can be piled without slumping. Zone of Transportation - Sediment transport is the movement of solid particles (sediment), typically due to a combination of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained. Zone of deposition - An area where snowfall is preferentially deposited, typically a lee slope. Zone of Aeration - The area of an unconfined aquifer above the water table where the pore spaces among soil particles and rock formations are filled with air. Cut Bank - A cut bank, also known as a river cliff or river-cut cliff, is the outside bank of a curve or meander in a water channel (stream), which is continually undergoing erosion. Incised Meander - a river meander which has been cut abnormally deeply into the landscape because uplift of the land has led to renewed downward erosion by the river. Yazoo Tributary - A Yazoo stream (also called a Yazoo tributary) is a geologic and hydrologic term for any tributary stream that runs parallel to, and within the floodplain of a larger river for considerable distance, before eventually joining it. Oblique angle - An angle that is not 90 degrees Angle of momentum - Angular momentum is a measure of the momentum of an object around an axis Cone of depression - A cone of depression occurs in an aquifer when groundwater is pumped from a well. In an unconfined aquifer (water table), this is an actual depression of the water levels. In confined aquifers (artesian), the cone of depression is a reduction in the pressure head surrounding the pumped well. Geyser - A geyser is a rare kind of hot spring that is under pressure and erupts, sending jets of water and steam into the air. Spring - A spring is a natural exit point at which groundwater emerges out of the aquifer and flows onto the top of the Earth's crust to become surface water. Angularity - Roundness or angularity is a measure of the smoothness of particles Sphericity - Sphericity is a measure of the degree to which a particle approximates the shape of a sphere, and is independent of its size. Limestone - Limestone is a sedimentary rock composed principally of calcium carbonate (calcite) or the double carbonate of calcium and magnesium (dolomite). Stalagmite - A stalagmite is an upward-growing mound of mineral deposits that have precipitated from water dripping onto the floor of a cave. Stalagtite - a tapering structure hanging like an icicle from the roof of a cave, formed of calcium salts deposited by dripping water. Aquiclude - An aquiclude is a geological formation that is impermeable to the flow of water Laminar Flow - In fluid dynamics, laminar flow is characterized by fluid particles following smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. Physical Abrasion - Abrasion in a stream or river channel occurs when the sediment carried by a river scours the bed and banks, contributing significantly to erosion. Lithification - lithification, the complex process whereby freshly deposited loose grains of sediment are converted into rock Channelization - Channelization is exactly what it sounds like, the human process of straightening and deepening channels in rivers. Capillary fringe - The capillary fringe is the subsurface layer in which groundwater seeps up from a water table by capillary action to fill pores. Cirque - Cirques are bowl-shaped, amphitheater-like depressions that glaciers carve into mountains and valley sidewalls at high elevations. Playa lake - A dry lake bed, also known as a playa, is a basin or depression that formerly contained a standing surface water body, which disappears when evaporation processes exceed recharge. Kettle Lake - A kettle is a depression or hole in an outwash plain formed by retreating glaciers or draining floodwaters. Graben Lake - A graben is a valley with a distinct escarpment on each side caused by the displacement of a block of land downward. Maar Lake - A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption. Paternoster Lake - A paternoster lake is one of a series of glacial lakes connected by a single stream or a braided stream system. Cryogenic lake - Cryogenic lakes form from the melting of permafrost. They often develop in polar latitudes. Doline - a shallow usually funnel-shaped depression of the ground surface formed by solution in limestone regions. (its a sinkhole) Caldera - A caldera is a large depression formed when a volcano erupts and collapses