Emma Pearce, University of Leeds, Leeds, United Kingdom, Adam D Booth, University of Leeds, School of Earth and Environment, Leeds, LS2, United Kingdom, Graham William Stuart, University of Leeds, School of Earth and Environment, Leeds, United Kingdom, Ian Jones, ION Geophysical Corporation, London, United Kingdom, Bryn P Hubbard, Aberystwyth University, Department of Geography and Earth Sciences, Aberystwyth, United Kingdom, Alex Brisbourne, NERC British Antarctic Survey, Cambridge, United Kingdom and Paul C Sava, Colorado School of Mines, Golden, CO, United States