Letter abstract
Nature Geoscience 2, 281 - 285 (2009)
Published online: 29 March 2009 | doi:10.1038/ngeo474
Subject Category: Palaeoclimate and palaeoceanography
Influence of Patagonian glaciers on Antarctic dust deposition during the last glacial period
David E. Sugden1, Robert D. McCulloch2, Aloys J.-M. Bory3,4 & Andrew S. Hein1
Ice cores provide a record of changes in dust flux to Antarctica, which is thought to reflect changes in atmospheric circulation and environmental conditions in dust source areas1, 2, 3, 4, 5, 6, 7, 8, 9. Isotopic tracers suggest that South America is the dominant source of the dust10, 11, 12, but it is unclear what led to the variable deposition of dust at concentrations 20–50 times higher than present in glacial-aged ice8, 9. Here we characterize the age and composition of Patagonian glacial outwash sediments, to assess the relationship between the Antarctic dust record from Dome C (refs 9, 13) and Patagonian glacial fluctuations14, 15, 16 for the past 80,000 years. We show that dust peaks in Antarctica coincide with periods in Patagonia when rivers of glacial meltwater deposited sediment directly onto easily mobilized outwash plains. No dust peaks were noted when the glaciers instead terminated directly into pro-glacial lakes. We thus propose that the variable sediment supply resulting from Patagonian glacial fluctuations may have acted as an on/off switch for Antarctic dust deposition. At the last glacial termination, Patagonian glaciers quickly retreated into lakes, which may help explain why the deglacial decline in Antarctic dust concentrations preceded the main phase of warming, sea-level rise and reduction in Southern Hemisphere sea-ice extent13.
- School of GeoSciences, University of Edinburgh, Edinburgh, EH8 9XP, UK
- School of Biological and Environmental Science, University of Stirling, Stirling, FK9 4LA, UK
- British Antarctic Survey, Cambridge, CB3 0ET, UK
- Present address: UMR GEOSYSTEMES, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France, and Lamont-Doherty Earth Observatory of Columbia University, New York 10964, USA
Correspondence to: David E. Sugden1 e-mail: David.Sugden@ed.ac.uk
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Palaeoclimate Patagonian dust machineNature Geoscience News and Views (01 Apr 2009)
Antarctic ice sheets at risk?Nature News and Views (29 Oct 1992)
RESEARCH
Southern Ocean sea-ice extent, productivity and iron flux over the past eight glacial cyclesNature Article (23 Mar 2006)
Climate and atmospheric history of the past 420,000 years from the Vostok ice core, AntarcticaNature Article (03 Jun 1999)
See all 35 matches for Research
