This analysis of maps, aerial photographs and satellite images has revealed that more surge-type glaciers exist on Disko Island than previously estimated. A total of 75 glaciers are classified as surge-type, constituting 30% of the glaciers larger than 1 km2 and 59% of the glacierised area. The duration of the surge cycle is 100 years or more. The quiescent phase can be divided into three periods: (1) an initial period, where the glacier terminus remains at the maximum position, (2) an intermediate period, where the debris-covered terminus is detached and the recession rate is as high as 250 m yr-1, and (3) a late period, where the recession rate is slow and the mass balance is positive. Due to the relatively long duration of the surge period, climate change may affect the frequency of surge events and the evolution of the quiescent phase. Especially, large glaciers with ablation areas facing in the arc south to northwest are sensitive to climatic variations (Yde and Knudsen, 2007). In this context, it must be emphasised that the potential of glacier surging has to be considered when paleoclimatic conditions (e.g. temperature) are interpreted from glacier fluctuations and moraine positions.
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