Simulation of fast-flow features of the Fennoscandian ice sheet during the Last Glacial MaximumP.-L. FORSSTRÖM, O. SALLASMAA, R. GREVE and T. ZWINGER AbstractIn order to reconstruct the paleo-glaciation in Fennoscandia and northern Asia during the late Weichselian ice age phase, simulations with the dynamic and thermodynamic ice-sheet model SICOPOLIS are carried out. Our focus is on the Last Glacial Maximum (LGM) around 20 ka BP. Climate forcing is based on mean annual surface temperature and precipitation derived from present data and PMIP UKMO21 results for the LGM. These distributions are interpolated via a glacial index defined by the GRIP delta-18-O record. The extent of the Scandinavian and the Barents ice sheets are reproduced in good agreement with the QUEEN reconstruction, but the Kara Sea and Taymyr Peninsula areas are too excessively glaciated. The fast-flow regions derived from the simulations, which are generally connected to regions with a temperate base and temperate ice above, are compared to hypothesized paleo-ice-stream locations, especially in the Norwegian Channel and the Baltic area. In the Norwegian Channel, temperate basal conditions with temperate ice above prevail and favour fast flow. In the Baltic area, ice-sheet advance is generally accompanied by slow ice velocities (under 200 m/a). Some temporary fast-flow features occur due to transitional temperate-base conditions, and higher velocities arise in retreat phases. Annals of Glaciology, 37, 383-389 (2003). |
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