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the solid crystalline form of water.

a mass of ice adhering to a mountainside.

white glare on the underside of low clouds indicating presence of ice which may be beyond the range of vision.

a floe smaller than 20 meters (66 feet) across.

pack ice from the point of view of the submariner.

a dome-shaped mass of glacier ice that spreads out in all directions; an ice cap is usually larger than an icefield but less than 50,000 square-kilometers (12 million acres).

a cave of ice, usually underneath a glacier and formed by meltwater; cave entrances are often enlarged near a glacier terminus by warm winds; most common on stagnant portions of glaciers.

a concentration of sea ice, covering 100's of square kilometers, which is found in the same region every summer.

the fraction of an area that is covered by sea ice.

the amount of ice contained in frozen or partially frozen soil or rock.

a core sample drilled from the accumulation of snow and ice over many years that have recrystallized and have trapped air bubbles from previous time periods, the composition of which can be used to reconstruct past climates and climate change; typically removed from an ice sheet (Antarctica and Greenland) or from high mountain glaciers elsewhere.

land overlaid at present by a glacier is said to be covered; the alternative term glacierized has not found general favour.

the boundary separating opposing flow directions of ice on a glacier or ice sheet.

the boundary at any given time between open water and sea, river or lake ice of any kind, whether drifting or fast; may be termed compacted when it is clear-cut, or open when it forms the indefinite edge of an area of dispersed ice.

the total area covered by some amount of ice, including open water between ice floes; ice extent is typically reported in square kilometers.

a cohesive sheet of ice floating in the water; the sea ice cover is made up of conglomerates of floes; ice floes are not unique to sea ice, as they also occur in rivers and lakes.

a suspension of numerous minute ice crystals in the air, reducing visibility at the earth's surface; the crystals often glitter in the sunshine; ice fog produces optical phenomena such as luminous pillars and small haloes.

a very narrow ice piedmont, extending less than about 1 km inland from the sea.

the vertical cliff forming the seaward face of an ice shelf or other floating glacier, varying in height from 2 to 50 meters (2.2 to 55 yards) above sea level.

a form of tabular berg found in the Arctic Ocean, with a thickness of 30 - 50 meters (33 to 55 yards) and an area from a few thousand square meters to 500 square kilometers (123,550 acres); ice islands often have an undulating surface, which gives them a ribbed appearance from the air.

an accumulation of broken river or sea ice caught in a narrow channel.

from the point of view of the submariner, a downward-projecting ridge on the underside of the ice canopy; the counterpart of a ridge; ice keels may extend as much as 50 meters (55 yards) below sea level.

a dominantly horizontal, lens-shaped body of ice of any dimension.

the average position of the ice edge in any given month or period based on observations over a number of years.

a research ship which performs ice surveys in polar regions.

precipitation of small balls or pieces of ice (hailstones) with a diameter ranging from 5 to 50 millimeters (0.2 to 2.0 inches), or sometimes more, falling either separately or agglomerated into irregular lumps; when the diameter is less that about 5 millimeters (0.2 inch), the balls are called ice pellets.

ice covering a costal strip of low-lying land backed by mountains; the surface of an ice piedmont slopes gently seawards and may be anything from 1 to 50 kilometers (0.6 to 31 miles) wide, fringing long stretches of coastline with ice cliffs; ice piedmonts frequently merge into ice shelves; a very narrow ice piedmont may be called an ice fringe.

a fall of unbranched ice crystals, in the form of needles, columns, or plates, often so tiny that they seem to be suspended in the air; these are visible mainly when they glitter in the sunshine (diamond dust); they may then produce a luminous pillar or other halo phenomena; this hydrometeor, which is frequent in polar regions, occurs at very low temperatures and in stable air masses.

a shaking of ice caused by crevasse formation or jerky motion.

a brittle, shiny crust of floating ice, formed on a quiet surface by direct freezing or from grease ice, usually in water of low salinity; thickness less than 5 centimeters (2 inches); easily broken by wind or swell, commonly breaking into rectangular pieces.

a mass of ice resting on rock and surrounded either by an ice shelf, or partly by an ice shelf and partly by sea; no rock is exposed and there may be none above sea level; ice rises often have a dome-shaped surface; the largest known is about 100 kilometers (62 miles) across.

the formation of discrete layers or lenses of segregated ice in freezing mineral or organic soils, as a result of the migration (and subsequent freezing) of pore water.

a dome-shaped mass of glacier ice that covers surrounding terrain and is greater than 50,000 square kilometers (12 million acres) (e.g., the Greenland and Antarctic ice sheets).

portion of an ice sheet that spreads out over water.

from the point of view of the submariner, thin places in the ice canopy, usually less than 1 meter (3.3 feet) thick and appearing from below as relatively light, translucent patches in dark surroundings; the under-surface of an ice skylight is normally flat; ice skylights are called large if big enough for a submarine to attempt to surface through them (120 meters, 131 yards), or small if not.

(1) a current of ice in an ice sheet or ice cap that flows faster than the surrounding ice (2) sometimes refers to the confluent sections of a branched-valley glacier (3) obsolete synonym of valley glaciers.

an ice-filled crack or fissure in the ground.

an ice cliff forming the seaward margin of an inland ice sheet, ice piedmont or ice rise; the rock basement may be at or below sea level.

narrow ice mass that is 3 to 4 meters (10 to 13 feet) wide at the ground surface, and extends as much as 10 meters (33 feet) down; a decrease in temperature during the winter leads to ice wedge cracks in the ground around ice wedges; during the summer, these cracks accumulate melt-water and sediment, forming pseudomorphs.

an oligochaete worm that lives on temperate glaciers or perennial snow; there are several species that range in color from yellowish-brown to reddish-brown or black; they are usually less than 1 millimeter (0.04 inch) in diameter and average about 3 millimeters (0.1 inch) long; some eat red algae.

permafrost that contains ice.

ice-bearing permafrost in which the soil particles are cemented together by ice.

a rock glacier that has interstitial ice a meter or so below the surface.

a rock glacier that has a buried core of ice.

topography that is due almost solely to differences in the amount of excess ice underlying its surface.

the temperature at which ice first forms during freezing of a soil/water system that does not initially contain ice.

permafrost containing excess ice.

a filling of sediment in the space formerly occupied by an ice wedge.

a polygon outlined by ice wedges underlying its boundaries.

a piece of ice that has broken off from the end of a glacier that terminates in water.

a major accumulation of icebergs projecting from the coast, held in place by grounding and joined together by fast ice.

a harbour, inlet, etc, is said to be icebound when navigation by ships is prevented due to ice, except possibly with the assistance of an icebreaker.

part of a glacier with rapid flow and a chaotic crevassed surface; occurs where the glacier bed steepenes or narrows.

a mass of glacier ice; similar to an ice cap, and usually smaller and lacking a dome-like shape; somewhat controlled by terrain.

a narrow fringe of ice attached to the coast, unmoved by tides and remaining after the fast ice has broken free.

the low pressure center near Iceland (mainly between Iceland and southern Greenland); on mean charts of sea-level pressure, it is a principal center of action in the atmosphere circulation of the northern hemisphere.

an embayment in an ice front, often of temporary nature, where ships can moor alongside and unload directly into the ice shelf.

hanging spike of clear ice formed by the freezing of dripping water.

a qualitative term describing the quantity of ice in frozen ground.

a sheetlike mass of layered ice formed on the ground surface, or on river or lake ice, by freezing of successive flows of water that may seep from the ground, flow from a spring or emerge from below river or lake ice through fractures.

a seasonal frost mound consisting only of ice and formed at least in part through lifting of one or more layers of an icing by injected water.

an area kept clear of trees and shrubs by the annual occurrence of icings.

a seasonal frost mound consisting exclusively of thinly layered ice, formed by freezing of successive flows of water issuing from the ground or from below river ice.

an ice wedge that is no longer growing.

a mass of rock fragments and finer material, on a slope, that contains either an ice core or interstitial ice, and shows evidence of past, but not present, movement.

electromagnetic radiation of wavelengths between approximately 0.75 and 1000 millimeters; see also atmospheric radiation, terrestrial radiation, longwave radiation.

an ice sheet of considerable thickness and an area of more than about 50,000 square kilometers (12.4 million acres), resting on rock; inland ice sheets near sea level may merge into ice shelves.

(1) exposure of an object to the sun (2) intensity of incoming solar radiation incident on a unit horizontal surface at a specific level.

structure to protect certain instruments from insolation and weather while at the same time ensuring sufficient ventilation.

water that forms transition layers at mineral/water and mineral/water/ice interfaces in frozen ground.

(1) (North American usage) permafrost underlying 35 - 65% of the area of exposed land surface (2) (Russian usage) permafrost underlying 40 - 60% of the area of exposed land surface.

a measure of the compactness, or strength of the ice; plays an important role in the deformation of the ice and formation of features such as ridges and leads.

ice formed in narrow spaces between small rocks and sediment in soil.

water occurring in unfrozen zones (taliks and cryopegs) within permafrost.

ice formed from water injected into soils or rocks.

in meteorology, a departure from the usual (normal) decrease or increase with altitude of the value of an atmospheric property; also, the layer through which this departure occurs (the inversion layer); this term almost always refers to a temperature inversion.

a distinct soil micromorphology, resulting from the effects of freezing and thawing processes, in which soil particles form subhorizontal layers of similar thickness.

a line of equal or constant pressure; it most often refers to a line drawn through all points of equal atmospheric pressure.

a line drawn through geographical points recording equal amounts of precipitation during a specific period.

a body of unfrozen ground, that is perennially cryotic (T < 0 degrees Celsius) and entirely surrounded by perennially frozen ground.

permafrost underlying less than 10% of the exposed land surface.

a layer or body of unfrozen ground entirely surrounded by perennially frozen ground.

a line of equal or constant temperature.

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