Cryosphere glossary
cryofront
the boundary between cryotic and noncryotic ground as indicated by the position of the 0 degrees Celsius isotherm in the ground.
cryogenesis
the combination of thermophysical, physico-chemical and physico-mechanical processes occurring in freezing, frozen and thawing earth materials.
cryogenic aquiclude
a layer of ground which, because of its frozen state, has a low enough permeability to act as a confining bed for an aquifer.
cryogenic fabric
the distinct soil micromorphology resulting from the effects of freezing and thawing processes.
cryogenic temperature
in international materials science, this term refers to temperatures generally below -50 degrees Celsius, but usually to temperatures within a few degrees of absolute zero (-273 degrees Celsius).
cryolithology
the study of the genesis, structure and lithology of frozen earth materials.
cryopedology
the study of soils at temperatures below 0 degrees Celsius, with particular reference to soils subject to intensive frost action, and to soils overlying permafrost.
cryopeg
a layer of unfrozen ground that is perennially cryotic (forming part of the permafrost), in which freezing is prevented by freezing-point depression due to the dissolved-solids content of the pore water.
cryoplanation
the process through which cryoplanation terraces form.
cryoplanation terrace
a step-like or table-like bench cut in bedrock in cold climate regions.
cryosol
soil formed in either mineral or organic materials having permafrost either within 1 meter (3.3 feet) below the surface or, if the soil is strongly cryoturbated, within 2 meters (6.6 feet) below the surface, and having a mean annual ground temperature below 0 degrees Celsius.
cryosphere
one of the earth's spheres of irregular form existing in the zone of interaction of the atmosphere, hydrosphere and lithosphere, distinguished by negative or zero temperature and the presence of water in the solid or super-cooled state; the term refers collectively to the portions of the earth where water is in solid form, including snow cover, floating ice, glaciers, ice caps, ice sheets, seasonally frozen ground and perennially frozen ground (permafrost).
cryostructure
the structural characteristics of frozen earth materials.
cryosuction
a suction developed in freezing or partially frozen fine-grained materials as a result of temperature-dependent differences in unfrozen water content.
cryotexture
the textural characteristics of frozen, fine-grained organic and mineral earth materials cemented together with ice.
cryotic ground
soil or rock at temperatures of 0 degrees Celsius or lower.
cryoturbate
a body of earth material moved or disturbed by frost action.
cryoturbation
(1) (singular) a collective term used to describe all soil movements due to frost action (2) (plural) irregular structures formed in earth materials by deep frost penetration and frost action processes, and characterized by folded, broken and dislocated beds and lenses of unconsolidated deposits, included organic horizons and even bedrock.
cumuliform
like cumulus; generally descriptive of all clouds; vertical development in the form of rising mounds, domes or towers; driven by thermal convection and have vertical velocities greater than 1 meter (3.3 feet) per second.
cumulonimbus
a principal cloud type (cloud genus) of vertical development, exceptionally dense and vertically developed clouds, occurring either as isolated clouds or as a line or wall of clouds with separated upper portions; these clouds appear as mountains or huge towers, at least a part of the upper portions of which are usually smooth, fibrous, or striated, and almost flattened; this part often spreads out in the form of an anvil (incus) or vast plume; under the base of cumulonimbus, which is very dark, there frequently exist virga, precipitation, and low, ragged clouds, either merged with it or not; its precipitation is often heavy and always of a showery nature.