1. Centre for Glaciology, Department of Geography and Earth Sciences; Aberystwyth University; Aberystwyth UK
2. Now at British Geological Survey; Environmental Science Centre; Nottingham UK
3. School of Earth, Atmospheric and Environmental Sciences; University of Manchester; Manchester UK
4. Idaho National Laboratory; Idaho Falls Idaho USA
5. Institute of Arctic and Alpine Research, and Department of Geological Sciences; University of Colorado Boulder; Boulder Colorado USA