1. British Antarctic Survey; Natural Environment Research Council; Cambridge UK
2. Institute of Earth Sciences; University of Iceland; Reykjavík Iceland
3. Department of Earth and Space Sciences; University of Washington; Seattle Washington USA
4. CNRS, Laboratoire de Glaciologie et Géophysique de l′Environnement; Grenoble France
5. Laboratoire de Glaciologie et Géophysique de l′Environnement; Universite Grenoble Alpes; Grenoble France