1. School of Earth and Ocean Sciences, Cardiff University, Cardiff CF10 3AT, UK.
2. Alfred Wegener Institute, 27570 Bremerhaven, Germany.
3. Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455, USA.
4. Laboratoire de Glaciologie, CNRS and Joseph Fourier University, 38400 Grenoble, France.
5. Laboratoire Chrono-Environnement, 25000 Besançon, France.
6. Department of Earth Sciences and Climate Change Institute, University of Maine, Orono, ME 04469, USA.
7. Godwin Laboratory for Palaeoclimate Research, Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK.
8. British Antarctic Survey, Madingley Road, High Cross, Cambridge CB3 0ET, UK.