Relation of measured basal temperatures and the spatial distribution of the geothermal heat flux for the Greenland ice sheet

• Published in: Annals of Glaciology
• Main Author: Greve, Ralf
• Format: Article in Journal/Newspaper
• Language: English
• Published: International Glaciological Society
• Subjects: Greenland; Ice sheet; Modelling; Basal temperature; Geothermal heat flux; 452; Annals of Glaciology; Dye 3; Dye-3; GRIP; ice core; Ice Sheet
• Online Access: http://hdl.handle.net/2115/34545; https://doi.org/10.3189/172756405781812510

The thermomechanical, three-dimensional ice-sheet model SICOPOLIS is applied to the Greenland ice sheet. Simulations over two glacial–interglacial cycles are carried out, driven by a climatic forcing interpolated between present conditions and Last Glacial Maximum anomalies. Based on the global heat-flow representation by Pollack and others (1993), we attempt to constrain the spatial pattern of the geothermal heat flux by comparing simulation results to direct measurements of basal temperatures at the GRIP, NorthGRIP, Camp Century and Dye 3 ice-core locations. The obtained heatflux map shows an increasing trend from west to east, a high-heat-flux anomaly around NorthGRIP with values up to 135mWm–2 and a low-heat-flux anomaly around Dye 3 with values down to 20mWm–2. Validation is provided by the generally good fit between observed and measured ice thicknesses. Residual discrepancies are most likely due to deficiencies of the input precipitation rate and further variability of the geothermal heat flux not captured here.