Geophysical exploration of a West Antarctic subglacial lake

南极冰下湖是位于南极冰盖下地形空洞中的液态水体。在过去的十年里，它们吸引了相当大的科学兴趣，因为它们有望包含独特的微生物生命形式和过去气候变化的详细记录。这些内容的检查需要科学家深入湖泊，测量和采样湖水和沉积物。然而，还没有一个湖泊以这种方式被探索过。这种形式的直接分析只能在一个湖泊被地球物理方法充分表征后才能进行（以揭示冰基的形态和湖泊的水深）。在南极洲已知的145个冰下湖泊中，没有一个被测量到需要进行有意义的直接分析的水平。我们建议对南极洲西部埃尔斯沃思山脉附近的一个10公里长的冰下湖进行综合地球物理勘探，该湖名为冰下埃尔斯沃思湖。该项目的结果将是第一个完全特征化的冰下湖泊环境，并为未来的直接勘探奠定基础。数据分析和建模将在布里斯托大学、英国南极调查局和诺森比亚大学进行。冰的厚度将通过透冰雷达确定，水深将通过地震勘探确定，冰的流动和积累将通过直接的表面测量获得。一系列的数值模型将被用来了解湖泊的历史，冰在湖面上的流动和湖内的水循环。数据可视化将与Martin Jakobsson博士（合作者）一起进行。在这个项目之后，下一步将是向埃尔斯沃思湖发射探测器。一个由英国领导的小组已经组建起来，负责规划这项工作（见www.ggy.bris.ac.uk/ellsworth），并承担可以说是南极科学史上最期待和最引人注目的科学项目。因此，我们在这里提出的地球物理工作将在未来几年被认为是理解地球上最大的未开发栖息地之一的非常重要的第一步。

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.