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A
Arete (n.)A bedrock ridge formed by two glaciers eroding away on opposite sides of the ridge.
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C
Cirque (n.)A semi-circular or amphitheater-shaped bedrock feature created as glaciers scour back into the mountain where the snow and ice forming the glacier first accumulates. Also known as a corrie.
Crag and tail (n.)
Subglacial streamlined feature composed of part polished rock, part soft sediment deposited by the glacier.
Cryoturbations (n.)
Irregular structures resulting from the displacement of soil horizons under cryostatic pressure, within soils in a periglacial climate.
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D
Dead-ice topography (n.)Undulating landscape in which a disordered assemblage of knolls, mounds or ridges of glacial deposits with irregular depressions, pits or kettle holes that are commonly undrained and which may contain ponds and swamps.
Deglaciation (n.)
The period of time during which there is a net melting of ice, rather than a net accumulation and spreading out of ice i.e. the time during which climate is returning to an interglacial one.
Delta (n.)
Fan-shaped plain of alluvial sediments at river mouth upon entry into the sea or a lake which is crossed by many distributaries, often extending beyond the general trend of the coastline or lake-shore. Deltaic (adj.).
Drumlin (n)
Low smooth streamlined hill composed of glacial deposits.
Drumlinoid (adj.)
Assuming certain characteristics of a drumlin but not fully streamlined.
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E
Erratic (n.), (adj.)Rock moved by glacial or floating ice from its original outcrop.
Esker (n.)
Long narrow sinuous ridge of sand and gravel deposited by a subglacial stream and left behind after the ice melted.
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F
Fan (n.)Fan-shaped mass of sediments which have been deposited by fluvial processes; may be formed in a variety of situations and settings.
Fjiord (n.)
A U-shaped glacial trough that once was near sea level but is now a flooded, long, steep-walled ocean embayment.
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G
Geomorphology (n.)The study of landforms; the study of the surface forms of the Earth and their development. Geomorphological (adj.).
Glacial debris (n.)
Material being transported by a glacier in contact with glacier ice.
Glacial spillway (n.)
A deeply cut drainage channel which is a result of meltwater erosion following the bursting of a glacial lake.
Glaciation (n.)
The actions of glaciers and ice sheets including glacial erosion and deposition. Term also used to describe a period of time in the Earth's history when ice in the form of glaciers spread into areas that were free from it at other times. Glaciated (adj.).
Glaciofluvial (adj.)
Of or pertaining to rivers made up of meltwater from glaciers or ice sheets.
Glaciolacustrine (adj.)
Of or pertaining to lakes made up of meltwater from glaciers or ice sheets. These lakes may or may not be dammed on one or more sides by the ice itself.
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H
Hanging valley (n.)A valley eroded by a small tributary glacier, such that the elevation of the valley floor is higher than the elevation of the valley floor of the larger glacier that the small tributary glacier joined.
Hillocks (n.)
Small hills.
Hummocks (n.)
Small irregular-shaped hills, generally occurring in clusters.
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I
Ice contact face (n.)Steep slope on an ice marginal landform located in the place where the ice once supported the feature.
Ice margin (n.)
The edge of an ice sheet or glacier. Ice marginal (adj.), Ice marginally (adv.).
Ice oscillation (n.)
A fluctuation in the position of the ice margin caused by a forward movement of the ice, followed by a retreat. This may be repeated several times.
Ice stagnation (n.), (adj.)
The decay of ice; and pertaining to this decay. Also ice wastage.
Ice stream (n.)
A body of ice which moves independently of (and usually faster than) the rest of an ice sheet; this may be caused by troughs in the bed which channel fast flow, or the occurrence of soft, deformable sediment under the ice.
Ice wedge casts (n.)
Crack infilled with soil which has resulted from the intense freeze-thaw processes of a periglacial climate.
Interglacial (n.), (adj.)
The time interval between glacial stages; pertaining to this time.
Irish Sea Till (n.)
Clay-rich till found along the eastern seaboard of Ireland, and occurring as much as 12km inland, which was deposited by an ice stream which occupied the Irish Sea Basin during the last glaciation.
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K
Kame (n.)Mound, knob or ridge of stratified sand and gravel deposited by a subglacial stream.
Kamiform (adj.)
Kame-like.
Kame terrace (n.)
Terrace which is a remnant of a stream bed that has formed along a valley wall at an ice margin, usually composed of stratified sand and gravel.
Kame and kettle topography (n.)
Hummocky, disorganised landscape composed of numerous hillocks of sand and gravel interspersed with kettle holes.
Kettle hole (n.)
Rounded depression left behind when a (sometimes buried) block of 'dead' ice from an ice sheet melts.
Knock and lochan (a.)
Term descriptive of a glaciated landscape of low relief which is made up of ice-moulded hillocks and intervening lochans (small lakes) eroded along zones of rock weakness. Agglomerations of small roche moutonnees comprise knock and lochan topography.
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L
Lacustrine basin (n.)A generally rounded, relatively shallow depression which once held, or still holds, a lake. Lacustrine (adj.) is a term referring to sediments and processes of or pertaining to lakes.
Lodgement (n.), (adj.)
Process by which debris is released from the sliding base of a moving glacier/ice sheet and plastered or 'lodged' onto the glacier bed; also describes tills emplaced by this process.
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M
Melt-out (n.), (adj.)Process by which glacial debris is very slowly released from ice that is not sliding or deforming internally; also describes tills emplaced by this process.
Meltwater Channel (n.)
Deeply cut drainage channel which is a result of meltwater erosion during ice wastage.
Moraine (n.)
Mound or ridge of unsorted and unstratified glacial debris, deposited commonly at the ice margin. Morainic (adj.).
Terminal moraine/end-moraine
A moraine left where the ice melts at the lower end, or margin, of a glacier or ice sheet.
Lateral moraine
A moraine formed by rock material falling on the sides of a glacier from the sides of the valley.
Morphology (n.)
The form and structure of the land surface in an area or place. Morphological (adj.), Morphologically (adv.).
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N
Nunatak (n.)Exposed area, usually a mountain peak, protruding above the ice of an ice sheet/glacier.
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O
Outwash (adj.)Synonymous with glaciofluvial (of or pertaining to rivers made up of meltwater from glaciers or ice sheets). Hence outwash fans, outwash plains and outwash terraces.
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P
Peat (n.)An accumulation of vegetable matter at the EarthÕs surface that has partially decomposed.
Periglacial (adj.)
Refers to the area on the borders of an ice sheet. The word 'periglacial' is used both for the geographical area and for the physical conditions in it. Periglacially (adv.).
Proglacial (adj.)
In front of a glacier. Proglacially (adv.).
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Q
Quaternary (n.), (adj.)The period of geological time from 1.6 million years ago to the present, subdivided into two Epochs, the Pleistocene and the Holocene; pertaining to that time.
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R
Roche moutonnee (n.)Ice-sculpted rock form with elongate, smooth and domed surface, long-axis oriented in direction of ice movement.
Ribbon lake (n.)
A lake which is part of a chain of lakes in a glacial valley. Also known as a Paternoster lake.
Rogen moraine (n.)
Subglacial ridge formed transverse to ice flow, with distinctive streamlined upper surfaces. Not to be confused with terminal moraines; rogen moraines are formed beneath the ice.
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S
Sandur (n.) (sandar, pl.)A low-angle fan or sheet of outwash gravels deposited in front of an ice sheet.
Sediment (n.)
Any material that has been obtained by earlier rocks by denudation, and subsequently redeposited.
Striae (n.)
Ice-scratches on rock surfaces caused by debris carried by moving ice. Striated (adj.).
Subglacial (adj.)
Referring to beneath the glacier or ice sheet. Subglacially (adv.).
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T
Till (n.)Sediment deposited by or from glacier ice; unsorted and unstratified, and generally tightly packed.
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U
U-shaped glacial trough (n.)Also known as trough valleys or U-shaped valleys, these are the steep walled, broad floored valleys with a shape considered diagnostic of former mountain glaciation. In contrast to the 'V' shape typical of river valleys.
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V
Varve (n.) A pair of thin sedimentary layers formed annually by seasonal climatic changes. Usually found in glacial lake deposits, varves consist of a coarse-grained, light-colored summer deposit and a finer-grained, dark-colored winter deposit formed when fine sediment settles out from the water under the ice cover.Back to top of the page
