Obliquity-paced Pliocene West Antarctic ice sheet oscillations

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doi: 10.1038/nature07867
Author(s): Naish, Tim; Powell, R.; Levy, R.; Wilson, G.; Scherer, R.; Talarico, F.; Krissek, L.; Niessen, F.; Pompilio, M.; Wilson, T.; Carter, L.; DeConto, R. M.; Huybers, P.; McKay, R.; Pollard, D.; Ross, J.; Winter, D.; Barrett, P.; Browne, G.; Cody, R.; Cowan, E.; Crampton, J.; Dunbar, G.; Florindo, F.; Gebhardt, C.; Graham, I.; Hannah, M.; Hansaraj, D.; Harwood, D.; Helling, D.; Henrys, S.; Hinnov, L.; Kuhn, G.; Kyle, P.; Läufer, A.; Maffioli, P.; Magens, D.; Mandernack, K.; McIntosh, W.; Millan, C.; Morin, R.; Ohneiser, C.; Paulsen, T.; Persico, D.; Raine, I.; Reed, J.; Riesselman, C.; Sagnotti, Leonardo; Schmitt, D.; Sjunneskog, C.; Strong, P.; Taviani, M.; Vogel, S.; Wilch, T.; Williams, T.
Author Affiliation(s): Primary:
Victoria University of Wellington, Antarctic Research Centre, Wellington, New Zealand
Northern Illinois University, United States
University of Nebraska-Lincoln, United States
University of Otago, New Zealand
Universita di Siena, Italy
Ohio State University, United States
Alfred Wegener Institute, Federal Republic of Germany
Istituto Nazionale di Geofisica e Vulcanologia, Italy
University of Massachusetts, Amherst, United States
Harvard University, United States
Pennsylvania State University, United States
New Mexico Institute of Mining & Technology, United States
Appalachian State University, United States
Johns Hopkins University, United States
Federal Institute of Geosciences & National Resources, Federal Republic of Germany
Universita Milano-Bicocca, Italy
Colorado School of Mines, United States
U. S. Geological Survey, United States
University of Wisconsin-Oshkosh, United States
Universita di Parma, Italy
Iowa State University, United States
Stanford University, United States
University of Alberta, Canada
Louisiana State University, United States
Albion College, United States
Lameont-Doherty Earth Observatory, United States
Volume Title: Nature (London)
Source: Nature (London), 458(7236), p.322-328. Publisher: Macmillan Journals, London, United Kingdom. ISSN: 0028-0836
Note: In English. 33 refs.; charts, sketch map
Summary: Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles. Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch (approx. 5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behavior in the context of future global warming. Here we present a marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf by the ANDRILL programme and demonstrate well-dated, approx. 40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth's axial tilt (obliquity) during the Pliocene. Our data provide direct evidence for orbitally induced oscillations in the WAIS, which periodically collapsed, resulting in a switch from grounded ice, or ice shelves, to open waters in the Ross embayment when planetary temperatures were up to approx 3 °C warmer than today and atmospheric CO2 concentration was as high as approx. 400 p.p.m.v. (mod. auth. abst.)
Year of Publication: 2009
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; ANDRILL; Antarctic ice sheet; Antarctica; Carbon dioxide; Cenozoic; Climate change; Climate forcing; Cores; Cycles; Debris; Deep Sea Drilling Project; Glacial geology; Ice rafting; Icebergs; Isotope ratios; Isotopes; Leg 119; Leg 178; Leg 188; Leg 28; Lithostratigraphy; Neogene; O-18/O-16; Obliquity of the ecliptic; Ocean Drilling Program; Orbital forcing; Oxygen; Paleoclimatology; Paleoenvironment; Pliocene; Quaternary; Sedimentary rocks; Sediments; Southern Ocean; Stable isotopes; Tertiary; West Antarctic ice sheet
Coordinates: S684114 S492407 E0855147 E0713936
S673400 S634800 W0640000 W0783000
S674500 S640000 E0750000 E0670000
Record ID: 2010038309
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