PREDICTING AND INVESTIGATING SUBGLACIAL LAKES OF THE FORMER BRITISH AND FENNOSCANDIAN ICE SHEETS

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The discovery that large lakes exist at the base of the Antarctic Ice Sheet and that these lakes can rapidly drain has major implications related to meltwater routing and supply and thus ice-sheet dynamics. Recent satellite observations show that subglacial lakes are very active, and can perturb the water system rapidly on annual or shorter time-scales, while at Byrd Glacier a direct link between water drainage and ice flow acceleration has been demonstrated. With over 250 lakes now known to exist under the Antarctic Ice Sheet there has also been rising interest in exploring these subglacial environments to look for evidence of life and to investigate their potential as long-term archives of climate change. This interest is demonstrated by three separate US-, Russian- and UK-led programs which aim to drill into these lakes. Despite the growing importance attached to studying subglacial lakes in Antarctica, the identification and study of palaeo subglacial lakes from former ice sheets has been neglible, with even fundamental questions related to their geological signatures remaining elusive. Yet investigations of palaeo subglacial lakes offers significant advantages because we have comprehensive information about the bed properties, they are logistically more accesable (i.e. on foot instead of 3 km long drills) and we can sample and examine the sediments with ease. If I can find palaeo subglacial lakes then I have the potential to make huge leaps in knowledge with regard to the topographic context and hydrological pathways that the phenomena form a part of; essentially I gain spatial and sedimentological information in relation to contemporary subglacial lake investigations and lose out on the short time dynamics. This proposal offers a pioneering study that aims to invigorate research on subglacial lakes by answering two major research questions: (1) can we successfully predict and identify subglacial lakes of the former British and Fennoscandian Ice Sheets during the last glaciation?; and (2) What impact did subglacial lakes have on meltwater routing and supply and thus ice sheet dynamics? The study will utilise GIS and numerical ice sheet modelling to predict where subglacial lakes may have ocurred in the former British and Fennoscandian Ice Sheets and then the identification and evaluation of some of these former subglacial lakes using sedimentological, stratigraphic and geomorphological techniques. The formulation of a diagnostic set of criteria for identying palaeo subglacial lakes is a major research objective for the project and will be first such attempted. Once identified further research will concentrate on the links between subglacial lakes and ice sheet dynamics, specifically related to meltwater routing and the relationship with ice streams. It is anticipate that findings arising from this work and the lakes I discover will stimulate many other researchers to exploit the record of palaeo subglacial lakes and set a new agenda for glaciological thinking of how basal water exerts a control on ice flux and routing.