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Anunatak (fromInuitnunataq) is the summit or ridge of a mountain that protrudes from an ice field orglacier that otherwise covers most of the mountain or ridge. They often form naturalpyramidal peaks. Isolated nunataks are also calledglacial islands,[2] and smaller nunataks rounded by glacial action may be referred to asrognons.[3][4]
The word is ofGreenlandic origin[5] and has been used in English since the 1870s.
The termnunatak is typically used in areas where a permanentice sheet is present and the ridge protrudes above the sheet.[6] Nunataks present readily identifiable landmark reference points in glaciers or ice caps and are often named. While some are isolated, they can also form dense clusters, such asQueen Louise Land in Greenland.[7]
Nunataks are generally angular and jagged, hampering the formation of glacial ice on their tops, although snow can accumulate on them. This can contrast strongly with the softer contours of the glacially eroded land after a glacier retreats. They are not greatly affected byfrost weathering, given the low frequency of freeze-thaw cycles in areas of ice caps and ice sheets.[8][page needed]
Typically nunataks are the only places where plant life can survive on ice sheets or ice caps. Lifeforms on nunataks are often isolated by the surrounding ice or glacier, providing unique habitats.[9]
Media related toNunataks at Wikimedia Commons