[1] Cardiff Univ, Sch Earth & Ocean Sci, Cardiff CF10 3AT, S Glam, Wales
[2] Alfred Wegener Inst, D-27570 Bremerhaven, Germany
[3] Univ Minnesota, Dept Earth Sci, Minneapolis, MN 55455 USA
[4] CNRS, Lab Glaciol, F-38400 Grenoble, France
[5] Univ Grenoble 1, F-38400 Grenoble, France
[6] Lab Chronoenvironm, F-25000 Besancon, France
[7] Univ Maine, Dept Earth Sci, Orono, ME 04469 USA
[8] Univ Maine, Climate Change Inst, Orono, ME 04469 USA
[9] Univ Cambridge, Godwin Lab Palaeoclimate Res, Dept Earth Sci, Cambridge CB2 3EQ, England
[10] British Antarctic Survey, Cambridge CB3 0ET, England