Keywords

Ablation - the melting of ice.
Active layer - An area of unfrozen ground which surrounds a glacier but is still part of an ecosystem.
Accumulation - gain in ice mass.
Equilibrium zone - The area where accumulation meets ablation rates
Glacier - a large, slow moving river of ice, formed from compacted layers of snow, that slowly deforms and flows in response to gravity and its own weight.
Glacial environment - an area which is influenced by glacial activity and in which distinctive landscapes and landforms are created due to processes of erosion and deposition.
Moraine - mounds of debris and material deposited by glaciers.
Periglacial environments - areas which are on the edge of glacial environments. They are characterised by permafrost and therefore have their own distinctive features.
Permafrost - a condition where a layer of sediment below the ground remains frozen for longer than a year. It occurs wherever the annual ground temperature is less than 0 degrees Celcius. Permafrost is fround in about 25% of the world's non-glacialated land surfaces.
Snout - the end of a glacier.
Talik - a localised, unfrozen layer of sediment which is sometimes found under lakes.
System - a system is a set of interacting components which form an integrated whole.
Glacial system - glacial systems have inputs, outputs and processes. The can be summarised as the glacial budget.
Calving - the formation of icebergs.
Zone of accumulation - the upper part of a glacier where inputs exceed outputs.
Zone of ablation - the lower part of a glacier where the outputs exceed the inputs
Closed talik - unfrozen ground that is found within a mass of permafrost.
Open talik - an area of unfrozen ground that is open to the ground surface but otherwise enclosed in permafrost.
Sporatic permafrost - occurs where small islands of permafrost are scattered in generally unfrozen areas.
Through talik - unfrozen ground that is exposed to the ground surface and to a larger mass of unfrozen ground beneath it.
Continuous permafrost - exists over the landscape as an uninterupted layer.
Discontinuous permafrost - zones of permafrost with numerous scattered small thawed areas.
Alpine permafrost - found at high elevations in areas outside of where continuous and discontinuous permafrost are common.
Subsea permafrost - is frozen ground that exists in the sediments beneath sea water.
Sub-glacial - The area below the glacier.
Supra-glacial - The area on top of the glacier.