Geophysical exploration of a West Antarctic subglacial lake

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Antarctic subglacial lakes are liquid bodies of water located in topographic hollows beneath the ice sheets of Antarctica. They have attracted considerable scientific interest over the last ten years as they are expected to contain unique microbial lifeforms and detailed records of past climate change. Examination of these contents requires scientists to penetrate into a lake, and measure and sample the lake water and sediment. No lake has yet to be explored in this way, however. This form of direct analysis can only take place once a lake has been characterised fully by geophysical methods (to uncover the morphology of the ice base and the water depth of the lake). Of the 145 known subglacial lakes in Antarctica none have been measured to the level required for meaningful direct analysis to take place. We propose to undertake a comprehensive geophysical exploration of a 10 km long subglacial lake in West Antarctica, near the Ellsworth Mountains, named Subglacial Lake Ellsworth. The result of the project will be the first fully characterised subglacial lake environment and the establishment of a candidate for future direct exploration. Data analysis and modelling will be undertaken at the University of Bristol, the British Antarctic Survey and Northumbria University. Ice thickness will be determined from ice-penetrating radar, water depths will be found using seismic exploration, and ice flow and accumulation will be obtained from direct surface measurements. A series of numerical models will be used to understand the history of the lake, the flow of ice across the lake and the circulation of water within the lake. Data visualisation will be undertaken in conjunction with Dr. Martin Jakobsson (collaborator). Following this project, the next step will be to send a probe into Lake Ellsworth. A UK-led team has been assembled to plan such work (see www.ggy.bris.ac.uk/ellsworth), and take on what is arguably the most eagerly awaited and high-profile scientific project in the history of Antarctic science. Hence, the geophysical work we propose here will be thought of, in years to come, as a hugely important first step towards the understanding of one of the greatest unexplored habitats on Earth.