Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica
Significantly reduced ice coverage in Greenland and West Antarctica during the warmer-than-present Pliocene could account for ∼10 m of global mean sea level rise. Any sea level increase beyond this would require contributions from the East Antarctic Ice Sheet (EAIS). Previous studies have presented...
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ftucl:oai:eprints.ucl.ac.uk.OAI2:10056957 2023-12-24T10:11:29+01:00 Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica Bertram, RA Wilson, DJ van de Flierdt, T McKay, RM Patterson, MO Jimenez-Espejo, FJ Escutia, C Duke, GC Taylor-Silva, BI Riesselman, CR 2018-07-15 text https://discovery.ucl.ac.uk/id/eprint/10056957/1/1-s2.0-S0012821X18302632-main%281%29.pdf https://discovery.ucl.ac.uk/id/eprint/10056957/ eng eng https://discovery.ucl.ac.uk/id/eprint/10056957/1/1-s2.0-S0012821X18302632-main%281%29.pdf https://discovery.ucl.ac.uk/id/eprint/10056957/ open Earth and Planetary Science Letters , 494 (C) pp. 109-116. (2018) East Antarctic Ice Sheet Wilkes Subglacial Basin provenance radiogenic isotopes Pliocene deglacial timescales Article 2018 ftucl 2023-11-27T13:07:29Z Significantly reduced ice coverage in Greenland and West Antarctica during the warmer-than-present Pliocene could account for ∼10 m of global mean sea level rise. Any sea level increase beyond this would require contributions from the East Antarctic Ice Sheet (EAIS). Previous studies have presented lowresolution geochemical evidence from the geological record, suggesting repeated ice advance and retreat in low-lying areas of the EAIS such as the Wilkes Subglacial Basin. However, the rates and mechanisms of retreat events are less well constrained. Here we present orbitally-resolved marine detrital sediment provenance data, paired with ice-rafted debris and productivity proxies, during three time intervals from the middle to late Pliocene at IODP Site U1361A, offshore of the Wilkes Subglacial Basin. Our new data reveal that Pliocene shifts in sediment provenance were paralleled by increases in marine productivity, while the onset of such changes was marked by peaks in ice-rafted debris mass accumulation rates. The coincidence of sediment provenance and marine productivity change argues against a switch in sediment delivery between ice streams, and instead suggests that deglacial warming triggered increased rates of iceberg calving, followed by inland retreat of the ice margin. Timescales from the onset of deglaciation to an inland retreated ice margin within the Wilkes Subglacial Basin are on the order of several thousand years. This geological evidence corroborates retreat rates determined from ice sheet modeling, and a contribution of ∼3 to 4 m of equivalent sea level rise from one of the most vulnerable areas of the East Antarctic Ice Sheet during interglacial intervals throughout the middle to late Pliocene. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Greenland Ice Sheet Iceberg* West Antarctica University College London: UCL Discovery Antarctic East Antarctica West Antarctica East Antarctic Ice Sheet Greenland Wilkes Subglacial Basin ENVELOPE(145.000,145.000,-75.000,-75.000) |
institution |
Open Polar |
collection |
University College London: UCL Discovery |
op_collection_id |
ftucl |
language |
English |
topic |
East Antarctic Ice Sheet Wilkes Subglacial Basin provenance radiogenic isotopes Pliocene deglacial timescales |
spellingShingle |
East Antarctic Ice Sheet Wilkes Subglacial Basin provenance radiogenic isotopes Pliocene deglacial timescales Bertram, RA Wilson, DJ van de Flierdt, T McKay, RM Patterson, MO Jimenez-Espejo, FJ Escutia, C Duke, GC Taylor-Silva, BI Riesselman, CR Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica |
topic_facet |
East Antarctic Ice Sheet Wilkes Subglacial Basin provenance radiogenic isotopes Pliocene deglacial timescales |
description |
Significantly reduced ice coverage in Greenland and West Antarctica during the warmer-than-present Pliocene could account for ∼10 m of global mean sea level rise. Any sea level increase beyond this would require contributions from the East Antarctic Ice Sheet (EAIS). Previous studies have presented lowresolution geochemical evidence from the geological record, suggesting repeated ice advance and retreat in low-lying areas of the EAIS such as the Wilkes Subglacial Basin. However, the rates and mechanisms of retreat events are less well constrained. Here we present orbitally-resolved marine detrital sediment provenance data, paired with ice-rafted debris and productivity proxies, during three time intervals from the middle to late Pliocene at IODP Site U1361A, offshore of the Wilkes Subglacial Basin. Our new data reveal that Pliocene shifts in sediment provenance were paralleled by increases in marine productivity, while the onset of such changes was marked by peaks in ice-rafted debris mass accumulation rates. The coincidence of sediment provenance and marine productivity change argues against a switch in sediment delivery between ice streams, and instead suggests that deglacial warming triggered increased rates of iceberg calving, followed by inland retreat of the ice margin. Timescales from the onset of deglaciation to an inland retreated ice margin within the Wilkes Subglacial Basin are on the order of several thousand years. This geological evidence corroborates retreat rates determined from ice sheet modeling, and a contribution of ∼3 to 4 m of equivalent sea level rise from one of the most vulnerable areas of the East Antarctic Ice Sheet during interglacial intervals throughout the middle to late Pliocene. |
format |
Article in Journal/Newspaper |
author |
Bertram, RA Wilson, DJ van de Flierdt, T McKay, RM Patterson, MO Jimenez-Espejo, FJ Escutia, C Duke, GC Taylor-Silva, BI Riesselman, CR |
author_facet |
Bertram, RA Wilson, DJ van de Flierdt, T McKay, RM Patterson, MO Jimenez-Espejo, FJ Escutia, C Duke, GC Taylor-Silva, BI Riesselman, CR |
author_sort |
Bertram, RA |
title |
Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica |
title_short |
Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica |
title_full |
Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica |
title_fullStr |
Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica |
title_full_unstemmed |
Pliocene deglacial event timelines and the biogeochemical response offshore Wilkes Subglacial Basin, East Antarctica |
title_sort |
pliocene deglacial event timelines and the biogeochemical response offshore wilkes subglacial basin, east antarctica |
publishDate |
2018 |
url |
https://discovery.ucl.ac.uk/id/eprint/10056957/1/1-s2.0-S0012821X18302632-main%281%29.pdf https://discovery.ucl.ac.uk/id/eprint/10056957/ |
long_lat |
ENVELOPE(145.000,145.000,-75.000,-75.000) |
geographic |
Antarctic East Antarctica West Antarctica East Antarctic Ice Sheet Greenland Wilkes Subglacial Basin |
geographic_facet |
Antarctic East Antarctica West Antarctica East Antarctic Ice Sheet Greenland Wilkes Subglacial Basin |
genre |
Antarc* Antarctic Antarctica East Antarctica Greenland Ice Sheet Iceberg* West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Greenland Ice Sheet Iceberg* West Antarctica |
op_source |
Earth and Planetary Science Letters , 494 (C) pp. 109-116. (2018) |
op_relation |
https://discovery.ucl.ac.uk/id/eprint/10056957/1/1-s2.0-S0012821X18302632-main%281%29.pdf https://discovery.ucl.ac.uk/id/eprint/10056957/ |
op_rights |
open |
_version_ |
1786165676308692992 |