1. British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK
2. Department of Geography, Science Laboratories, Durham University, South Road, Durham DH1 3LE, UK
3. National Oceanography Centre, European Way, Southampton SO14 3ZH, UK
4. Department of Geology and Environmental Geosciences, Northern Illinois University, 1425 West Lincoln Hwy, DeKalb, IL 60115-2828, USA
5. Earth and Planetary Sciences Department, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
6. Department of Applied Sciences, Northumbria University, Ellison Place 2, Newcastle-upon-Tyne NE1 8ST, UK
7. Keen Marine Limited, 15 Minerva Road, East Cowes, Isle of Wight PO32 6HD, UK
8. The Grantham Institute and Department of Earth Science and Engineering, Imperial College London, South Kensington, London SW7 2AZ, UK