Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene
The flux and provenance of ice-rafted detritus (IRD) deposited in the Southern Ocean can reveal information about the past instability of Antarctica's ice sheets during different climatic conditions. Here we present a Pliocene IRD provenance record based on the 40Ar/39Ar ages of ice-rafted horn...
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American Geophysical Union
2014
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Online Access: | http://nora.nerc.ac.uk/id/eprint/508049/ https://nora.nerc.ac.uk/id/eprint/508049/1/palo20109.pdf https://doi.org/10.1002/2014PA002625 |
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ftnerc:oai:nora.nerc.ac.uk:508049 2023-05-15T13:48:08+02:00 Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene Cook, C.P. Hill, D.J. van de Flierdt, Tina Williams, T. Hemming, S.R. Dolan, A.M. Pierce, E.L. Escutia, C. Harwood, D. Cortese, G. Gonzales, J.J. 2014 text http://nora.nerc.ac.uk/id/eprint/508049/ https://nora.nerc.ac.uk/id/eprint/508049/1/palo20109.pdf https://doi.org/10.1002/2014PA002625 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/508049/1/palo20109.pdf Cook, C.P.; Hill, D.J.; van de Flierdt, Tina; Williams, T.; Hemming, S.R.; Dolan, A.M.; Pierce, E.L.; Escutia, C.; Harwood, D.; Cortese, G.; Gonzales, J.J. 2014 Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene. Paleoceanography, 29 (6). 533-548. https://doi.org/10.1002/2014PA002625 <https://doi.org/10.1002/2014PA002625> Publication - Article PeerReviewed 2014 ftnerc https://doi.org/10.1002/2014PA002625 2023-02-04T19:40:07Z The flux and provenance of ice-rafted detritus (IRD) deposited in the Southern Ocean can reveal information about the past instability of Antarctica's ice sheets during different climatic conditions. Here we present a Pliocene IRD provenance record based on the 40Ar/39Ar ages of ice-rafted hornblende grains from Ocean Drilling Program Site 1165, located near Prydz Bay in the Indian Ocean sector of the Southern Ocean, along with the results of modeled sensitivity tests of iceberg trajectories and their spatial melting patterns under a range of sea surface temperatures (SSTs). Our provenance results reveal that IRD and hence icebergs in the Prydz Bay area were mainly sourced from (i) the local Prydz Bay region and (ii) the remote Wilkes Land margin located at the mouth of the low-lying Aurora Subglacial Basin. A series of IRD pulses, reaching up to 10 times background IRD flux levels, were previously identified at Site 1165 between 3.3 and 3.0 Ma. Our new results reveal that the average proportion of IRD sourced from distal Wilkes Land margin doubles after 3.3 Ma. Our iceberg trajectory-melting models show that slower iceberg melting under cooling SSTs over this middle Pliocene interval allowed Wilkes Land icebergs to travel farther before melting. Hence, declining SSTs can account for a large part of the observed IRD provenance record at Site 1165. In early Pliocene IRD layers, sampled at suborbital resolution around 4.6 Ma, we find evidence for significant increases in icebergs derived from Wilkes Land during very warm interglacials. This is suggestive of large-scale destabilization of the East Antarctic Ice Sheet in the Aurora Subglacial Basin, as far-traveled icebergs would have to overcome enhanced melting in warmer SSTs. Our results highlight the importance of considering SSTs when interpreting IRD flux and provenance records in distal locations. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Iceberg* Prydz Bay Southern Ocean Wilkes Land Natural Environment Research Council: NERC Open Research Archive Antarctic Southern Ocean Prydz Bay East Antarctic Ice Sheet Indian Wilkes Land ENVELOPE(120.000,120.000,-69.000,-69.000) Paleoceanography 29 6 533 548 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
The flux and provenance of ice-rafted detritus (IRD) deposited in the Southern Ocean can reveal information about the past instability of Antarctica's ice sheets during different climatic conditions. Here we present a Pliocene IRD provenance record based on the 40Ar/39Ar ages of ice-rafted hornblende grains from Ocean Drilling Program Site 1165, located near Prydz Bay in the Indian Ocean sector of the Southern Ocean, along with the results of modeled sensitivity tests of iceberg trajectories and their spatial melting patterns under a range of sea surface temperatures (SSTs). Our provenance results reveal that IRD and hence icebergs in the Prydz Bay area were mainly sourced from (i) the local Prydz Bay region and (ii) the remote Wilkes Land margin located at the mouth of the low-lying Aurora Subglacial Basin. A series of IRD pulses, reaching up to 10 times background IRD flux levels, were previously identified at Site 1165 between 3.3 and 3.0 Ma. Our new results reveal that the average proportion of IRD sourced from distal Wilkes Land margin doubles after 3.3 Ma. Our iceberg trajectory-melting models show that slower iceberg melting under cooling SSTs over this middle Pliocene interval allowed Wilkes Land icebergs to travel farther before melting. Hence, declining SSTs can account for a large part of the observed IRD provenance record at Site 1165. In early Pliocene IRD layers, sampled at suborbital resolution around 4.6 Ma, we find evidence for significant increases in icebergs derived from Wilkes Land during very warm interglacials. This is suggestive of large-scale destabilization of the East Antarctic Ice Sheet in the Aurora Subglacial Basin, as far-traveled icebergs would have to overcome enhanced melting in warmer SSTs. Our results highlight the importance of considering SSTs when interpreting IRD flux and provenance records in distal locations. |
format |
Article in Journal/Newspaper |
author |
Cook, C.P. Hill, D.J. van de Flierdt, Tina Williams, T. Hemming, S.R. Dolan, A.M. Pierce, E.L. Escutia, C. Harwood, D. Cortese, G. Gonzales, J.J. |
spellingShingle |
Cook, C.P. Hill, D.J. van de Flierdt, Tina Williams, T. Hemming, S.R. Dolan, A.M. Pierce, E.L. Escutia, C. Harwood, D. Cortese, G. Gonzales, J.J. Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene |
author_facet |
Cook, C.P. Hill, D.J. van de Flierdt, Tina Williams, T. Hemming, S.R. Dolan, A.M. Pierce, E.L. Escutia, C. Harwood, D. Cortese, G. Gonzales, J.J. |
author_sort |
Cook, C.P. |
title |
Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene |
title_short |
Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene |
title_full |
Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene |
title_fullStr |
Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene |
title_full_unstemmed |
Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene |
title_sort |
sea surface temperature control on the distribution of far-traveled southern ocean ice-rafted detritus during the pliocene |
publisher |
American Geophysical Union |
publishDate |
2014 |
url |
http://nora.nerc.ac.uk/id/eprint/508049/ https://nora.nerc.ac.uk/id/eprint/508049/1/palo20109.pdf https://doi.org/10.1002/2014PA002625 |
long_lat |
ENVELOPE(120.000,120.000,-69.000,-69.000) |
geographic |
Antarctic Southern Ocean Prydz Bay East Antarctic Ice Sheet Indian Wilkes Land |
geographic_facet |
Antarctic Southern Ocean Prydz Bay East Antarctic Ice Sheet Indian Wilkes Land |
genre |
Antarc* Antarctic Ice Sheet Iceberg* Prydz Bay Southern Ocean Wilkes Land |
genre_facet |
Antarc* Antarctic Ice Sheet Iceberg* Prydz Bay Southern Ocean Wilkes Land |
op_relation |
https://nora.nerc.ac.uk/id/eprint/508049/1/palo20109.pdf Cook, C.P.; Hill, D.J.; van de Flierdt, Tina; Williams, T.; Hemming, S.R.; Dolan, A.M.; Pierce, E.L.; Escutia, C.; Harwood, D.; Cortese, G.; Gonzales, J.J. 2014 Sea surface temperature control on the distribution of far-traveled Southern Ocean ice-rafted detritus during the Pliocene. Paleoceanography, 29 (6). 533-548. https://doi.org/10.1002/2014PA002625 <https://doi.org/10.1002/2014PA002625> |
op_doi |
https://doi.org/10.1002/2014PA002625 |
container_title |
Paleoceanography |
container_volume |
29 |
container_issue |
6 |
container_start_page |
533 |
op_container_end_page |
548 |
_version_ |
1766248771336798208 |