1. Department of Oceanography; Dalhousie University; Halifax Nova Scotia Canada
2. Lamont-Doherty Earth Observatory; Columbia University; Palisades New York USA
3. Department of Earth and Environmental Sciences; Columbia University; Palisades New York USA
4. Institute of Geological Sciences and Oeschger Centre for Climate Change Research; University of Bern; Bern Switzerland
5. Institute of Earth Sciences; University of Heidelberg; Heidelberg Germany
6. Department of Earth and Atmospheric Sciences; Cornell University; Ithaca New York USA
7. Institute for Geophysics and Meteorology; University of Cologne; Cologne Germany