an aquifer in which an impermeable dirt/rock layer exists that prevents water from seeping into the aquifer from the ground surface located directly above.
those into which water seeps from the ground surface directly above the aquifer
A water-saturated sediment or rock whose permeability is so low it cannot transmit any useful amount of water.
a well in which water is under pressure
Cone of depression
occurs in an aquifer when groundwater is pumped from a well.
the gradual caving in or sinking of an area of land.
a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum; characterized by underground drainage systems with sinkholes, dolines, and caves.
the frozen water part of the Earth system.
a slowly moving mass or river of ice formed by the accumulation and compaction of snow on mountains or near the poles.
Zone of accumulation
the part of a glacier's surface, usually at higher elevations, on which there is net accumulation of snow, which subsequently turns into firn and then glacier ice.
Zone of ablation
the low-altitude area of a glacier or ice sheet below firn with a net loss in ice mass due to melting, sublimation, evaporation, ice calving, aeolian processes like blowing snow, avalanche, and any other ablation.
a glacial phenomenon that is responsible for the erosion and transportation of bedrock, especially large "joint blocks".
the mechanical scraping of a rock surface by friction between rocks and moving particles during their transport by wind, glacier, waves, gravity, running water or erosion.
a deep crack, or fracture, found in an ice sheet or glacier, as opposed to a crevice that forms in rock.
a crevasse that commonly opens across a glacier where the slope of its floor abruptly steepens.
a crevasse roughly parallel to the direction of ice movement that forms where a glacier spreads laterally.
a moraine deposited at the point of furthest advance of a glacier or ice sheet.
a deposit of clay, silt, sand, and gravel left by flowing streams in a river valley or delta, typically producing fertile soil.
all material of glacial origin found anywhere on land or at sea, including sediment and large rocks
unsorted material deposited directly by glacial ice and showing no stratification.
the fraction of solar energy (shortwave radiation) reflected from the Earth back into space.
a landform that forms at the mouth of a river, where the river flows into an ocean, sea, estuary, lake, or reservoir.
a bend in a sinuous watercourse or river. A meander forms when moving water in a stream erodes the outer banks and widens its valley, and the inner part of the river has less energy and deposits silt.