Evolution of the Eurasian Ice Sheets during the Last Deglaciation (25-10 kyr)

Friday, 19 December 2014
Anna L C Hughes1,2, Richard Gyllencreutz3, Jan Mangerud1,2, John Inge Svendsen1,2 and Øystein S Lohne4, (1)University of Bergen, Department of Earth Science, Bergen, Norway, (2)Bjerknes Centre for Climate Research, Bergen, Norway, (3)Stockholm University, Stockholm, Sweden, (4)Sweco Norge AS, Bergen, Norway
Both the timing of maximum extent and subsequent pace of retreat of the interconnected Eurasian (British-Irish, Scandinavian, Svalbard-Barents-Kara Sea) Ice Sheets were spatially variable likely reflecting contrasts in response to forcing mechanisms, geographical settings and glacial dynamics both between individual ice sheets and ice-sheet sectors. For example the maximum limit along the western continental shelf edge was reached up to 3,000 years earlier than the maximum, mainly terrestrial, limits in the east. We present new time-slice reconstructions of the ice-sheet evolution through the last deglaciation based on a compiled chronology of over 5,000 dates and published ice-margin positions. Ice-sheet margins are depicted every 1,000 years (25-10 kyr) and include uncertainty estimates (represented by maximum, minimum and most-credible lines). The new ice-sheet scale reconstructions summarise and provide the means for direct comparison of the empirical geological record against simulations of the deglacial ice-sheet evolution from numerical and isostatic ice-sheet modelling and the timing of abrupt events observed in deglacial climate and ocean records. The reconstruction process has identified both instances of conflicting evidence and gaps in the geological record that should be a focus for future studies. This work is part of an on-going project to reconstruct the changing limits of the Eurasian Ice Sheets through the last glacial cycle (www.uib.no/project/dated).