(Table S1) Chronostratigraphic constrains for sediment core AND1-1B

DOI

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 (Hays et al., 1976, doi:10.1126/science.194.4270.1121), fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles (Raymo and Huybers, 2008, doi:10.1038/nature06589). Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch (~5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming (Solomon et al., 2007). 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, ~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 ~3° C warmer than today ( Kim and Crowley, 2000, doi:10.1029/1999PA000459) and atmospheric CO2 concentration was as high as ~400 p.p.m.v. (van der Burgh et al., 1993, doi:10.1126/science.260.5115.1788, Raymo et al., 1996, doi:10.1016/0377-8398(95)00048-8). The evidence is consistent with a new ice-sheet/ice-shelf model (Pollard and DeConto, 2009, doi:10.1038/nature07809) that simulates fluctuations in Antarctic ice volume of up to +7 m in equivalent sea level associated with the loss of the WAIS and up to +3 m in equivalent sea level from the East Antarctic ice sheet, in response to ocean-induced melting paced by obliquity. During interglacial times, diatomaceous sediments indicate high surface-water productivity, minimal summer sea ice and air temperatures above freezing, suggesting an additional influence of surface melt (Huybers, 2006, doi:10.1126/science.1125249) under conditions of elevated CO2.

Biostratigraphic event ages include the maximum and minimum age identified in the CONOP constrained Southern Ocean diatom biochronologic calibration of Cody et al. (2008, doi:10.1016/j.palaeo.2007.08.020), except FO of Thalassiosira complicata and FO Rhizosolenia sp. D which are new (unpublished) ages determined in recent model runs (Cody et al., submitted).

Supplement to: Naish, Tim R; Powell, Ross; Levy, Richard H; Wilson, Gary S; Scherer, Reed P; Talarico, Franco M; Krissek, Lawrence A; Niessen, Frank; Pompilio, Massimo; Wilson, Terry; Carter, Lionel; DeConto, Robert M; Huybers, Peter; McKay, Robert M; Pollard, David; Ross, J; Winter, Diane M; Barrett, Peter J; Browne, G; Cody, Rosemary; Cowan, Ellen A; Crampton, James; Dunbar, Gavin B; Dunbar, Nelia W; Florindo, Fabio; Gebhardt, Catalina; Graham, I J; Hannah, Mike J; Hansaraj, D; Harwood, David M; Helling, D; Henrys, Stuart A; Hinnov, Linda A; Kuhn, Gerhard; Kyle, Philip R; Läufer, Andreas; Maffioli, P; Magens, Diana; Mandernack, Kevin W; McIntosh, W C; Millan, C; Morin, Roger H; Ohneiser, Christian; Paulsen, Timothy S; Persico, Davide; Raine, J Ian; Reed, J; Riesselman, Christina R; Sagnotti, Leonardo; Schmitt, Douglas R; Sjunneskog, Charlotte; Strong, P; Taviani, Marco; Vogel, Stefan; Wilch, T; Williams, Trevor (2009): Obliquity-paced Pliocene West Antarctic ice sheet oscillations. Nature, 458(7236), 322-329

Identifier
DOI https://doi.org/10.1594/PANGAEA.769658
Related Identifier https://doi.org/10.1038/nature07867
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.769658
Provenance
Creator Naish, Tim R ORCID logo; Powell, Ross; Levy, Richard H ORCID logo; Wilson, Gary S ORCID logo; Scherer, Reed P; Talarico, Franco M ORCID logo; Krissek, Lawrence A; Niessen, Frank ORCID logo; Pompilio, Massimo ORCID logo; Wilson, Terry; Carter, Lionel; DeConto, Robert M; Huybers, Peter ORCID logo; McKay, Robert M ORCID logo; Pollard, David; Ross, J; Winter, Diane M; Barrett, Peter J; Browne, G; Cody, Rosemary; Cowan, Ellen A ORCID logo; Crampton, James ORCID logo; Dunbar, Gavin B; Dunbar, Nelia W (ORCID: 0000-0002-5181-937X); Florindo, Fabio ORCID logo; Gebhardt, Catalina ORCID logo; Graham, I J; Hannah, Mike J; Hansaraj, D; Harwood, David M ORCID logo; Helling, D; Henrys, Stuart A ORCID logo; Hinnov, Linda A ORCID logo; Kuhn, Gerhard ORCID logo; Kyle, Philip R; Läufer, Andreas; Maffioli, P; Magens, Diana; Mandernack, Kevin W; McIntosh, W C; Millan, C; Morin, Roger H; Ohneiser, Christian ORCID logo; Paulsen, Timothy S; Persico, Davide ORCID logo; Raine, J Ian ORCID logo; Reed, J; Riesselman, Christina R ORCID logo; Sagnotti, Leonardo (ORCID: 0000-0003-3944-201X); Schmitt, Douglas R ORCID logo; Sjunneskog, Charlotte; Strong, P; Taviani, Marco ORCID logo; Vogel, Stefan ORCID logo; Wilch, T; Williams, Trevor
Publisher PANGAEA
Publication Year 2009
Funding Reference German Research Foundation https://doi.org/10.13039/501100001659 Crossref Funder ID 5472008 https://gepris.dfg.de/gepris/projekt/5472008 Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 129 data points
Discipline Earth System Research
Spatial Coverage (167.089 LON, -77.889 LAT)
Temporal Coverage Begin 2006-10-31T00:00:00Z
Temporal Coverage End 2006-12-26T00:00:00Z