Modelling of the thermal conditions at the Greenland ice sheet margin during Holocene deglaciation: boundary conditions for moraine formation
The specific geomorphological problem adressed in this paper is which thermal conditions determined moraine formation in west Greenland during Holocenedeglaciation. Ice sheet modelling and geothermal research are used to delineate boundary conditions for landform formation and hereby improve and evaluategeomorphologiacal hypotheses concerning moraine formation. Marginal thermal conditions are reconstructed from modelled basal temperature and estimatesof Mean Annual ground Surface Temperature (MAST) contemporaneous to moraine formation. In mountainous areas with an altitude above 800m, ice marginmorphology will be characterized by landforms typical for cold conditions owing to the combination of relatively thin ice ice throughout Holocenedeglaciation and pronounced negatice MAST values in the proglacial area. Low lying areas (0 - 250m), with a sufficient areal extension in the direction of iceflow, have relatively thick ice throughout Holocene deglaciation. The combination of basal temperatures at the pressure melting point with positive MASTvalues in the proglacial area is postulated to produce deposits related to temperate beds and margins.