1. Centre for Quaternary Research, Department of Geography, Royal Holloway; University of London; Egham Surrey TW200EX UK
2. University of Bern and Oeschger Centre for Climate Change Research; Bern Switzerland
3. Department of Geography; University of Oregon; Eugene OR 97403-1251 USA
4. College of Earth, Ocean, and Atmospheric Sciences; Oregon State University; Corvallis OR 97331-5503 USA