Bernd Kulessa1, Kerry Key2, Sarah Thompson1, Martin Siegert3
1Glaciology Group, College of Science, Swansea University, UK, 2Lamont-Doherty Earth Observatory, Columbia University, USA, 3Grantham Institute, and Department of Earth Science and Engineering, Imperial College London, UK
Numerical models of contemporary as well as palaeo ice sheets suggest that groundwater and heat exchanges between subglacial sedimentary basins and the ice sheet above can be substantial and influence the ice flow. A strategy for the measurement and assessment of such fluxes beneath contemporary ice sheet has not so far been available, however. Here we summarise, first, existing evidence for groundwater and heat exchanges between contemporary and palaeo ice sheets and the substrate below. Second we explain the utility of electromagnetic (EM) geophysical measurements in elucidating such exchanges, and present magnetotelluric (MT) forward models of the deep sedimentary basin beneath the Institute Ice Stream in West Antarctica by way of illustration. Third we propose a simple empirical model by which heat exchanges between subglacial sedimentary basins and the overlying ice sheet can be estimated to first-order from electromagnetic data. We then apply this model to existing Antarctic magnetotelluric data and discuss upcoming field electromagnetic projects on the Whillans and Institute Ice Streams in West Antarctica.