Timing of the descent into the last ice age determined by the bipolar seesaw
We present planktonic foraminiferal fauna and isotope records from the SE Atlantic that highlight the nature of millennial-scale variability over the last 100 kyr. We derive an hypothesis-driven age model for our records based on the empirical link between variations in Greenland temperature, ocean...
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Language: | English |
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American Geophysical Union
2014
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Online Access: | https://orca.cardiff.ac.uk/id/eprint/59720/ https://doi.org/10.1002/2014PA002623 https://orca.cardiff.ac.uk/id/eprint/59720/1/Wiley-20142015-01.pdf |
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:59720 2023-05-15T16:29:26+02:00 Timing of the descent into the last ice age determined by the bipolar seesaw Barker, Stephen Diz, Paula 2014-06-01 application/pdf https://orca.cardiff.ac.uk/id/eprint/59720/ https://doi.org/10.1002/2014PA002623 https://orca.cardiff.ac.uk/id/eprint/59720/1/Wiley-20142015-01.pdf en eng American Geophysical Union https://orca.cardiff.ac.uk/id/eprint/59720/1/Wiley-20142015-01.pdf Barker, Stephen https://orca.cardiff.ac.uk/view/cardiffauthors/A015364W.html orcid:0000-0001-7870-6431 orcid:0000-0001-7870-6431 and Diz, Paula 2014. Timing of the descent into the last ice age determined by the bipolar seesaw. Paleoceanography 29 (6) , pp. 489-507. 10.1002/2014PA002623 https://doi.org/10.1002/2014PA002623 file https://orca.cardiff.ac.uk/59720/1/Wiley-20142015-01.pdf doi:10.1002/2014PA002623 cc_by CC-BY Article PeerReviewed 2014 ftunivcardiff https://doi.org/10.1002/2014PA002623 2022-10-27T22:38:44Z We present planktonic foraminiferal fauna and isotope records from the SE Atlantic that highlight the nature of millennial-scale variability over the last 100 kyr. We derive an hypothesis-driven age model for our records based on the empirical link between variations in Greenland temperature, ocean circulation and carbonate preservation in the deep SE Atlantic. Our results extend earlier findings of an anti-phase (seesaw) relationship between north and south for the largest abrupt events of Marine Isotope Stage (MIS) 3-2 and the last deglaciation. In particular we find that Heinrich Stadials were paralleled by inferred southward shifts of the thermal Subtropical Front. These were followed by pronounced rebounds of the front with the return to interstadial conditions in the north. Our results also shed light on the mechanism of glaciation. In contrast to the last deglaciation, which was a globally symmetric change superposed by interhemispheric asynchronicity, we find that the descent into full glacial conditions at the onset of MIS 4 (~70 ka) displayed interhemispheric synchrony. We suggest that this globally synchronous descent into glacial MIS 4 was preconditioned by orbital changes but that the timing was ultimately determined by abrupt changes in ocean / atmosphere circulation patterns i.e. the bipolar seesaw. Article in Journal/Newspaper Greenland Cardiff University: ORCA (Online Research @ Cardiff) Greenland Paleoceanography 29 6 489 507 |
institution |
Open Polar |
collection |
Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
English |
description |
We present planktonic foraminiferal fauna and isotope records from the SE Atlantic that highlight the nature of millennial-scale variability over the last 100 kyr. We derive an hypothesis-driven age model for our records based on the empirical link between variations in Greenland temperature, ocean circulation and carbonate preservation in the deep SE Atlantic. Our results extend earlier findings of an anti-phase (seesaw) relationship between north and south for the largest abrupt events of Marine Isotope Stage (MIS) 3-2 and the last deglaciation. In particular we find that Heinrich Stadials were paralleled by inferred southward shifts of the thermal Subtropical Front. These were followed by pronounced rebounds of the front with the return to interstadial conditions in the north. Our results also shed light on the mechanism of glaciation. In contrast to the last deglaciation, which was a globally symmetric change superposed by interhemispheric asynchronicity, we find that the descent into full glacial conditions at the onset of MIS 4 (~70 ka) displayed interhemispheric synchrony. We suggest that this globally synchronous descent into glacial MIS 4 was preconditioned by orbital changes but that the timing was ultimately determined by abrupt changes in ocean / atmosphere circulation patterns i.e. the bipolar seesaw. |
format |
Article in Journal/Newspaper |
author |
Barker, Stephen Diz, Paula |
spellingShingle |
Barker, Stephen Diz, Paula Timing of the descent into the last ice age determined by the bipolar seesaw |
author_facet |
Barker, Stephen Diz, Paula |
author_sort |
Barker, Stephen |
title |
Timing of the descent into the last ice age determined by the bipolar seesaw |
title_short |
Timing of the descent into the last ice age determined by the bipolar seesaw |
title_full |
Timing of the descent into the last ice age determined by the bipolar seesaw |
title_fullStr |
Timing of the descent into the last ice age determined by the bipolar seesaw |
title_full_unstemmed |
Timing of the descent into the last ice age determined by the bipolar seesaw |
title_sort |
timing of the descent into the last ice age determined by the bipolar seesaw |
publisher |
American Geophysical Union |
publishDate |
2014 |
url |
https://orca.cardiff.ac.uk/id/eprint/59720/ https://doi.org/10.1002/2014PA002623 https://orca.cardiff.ac.uk/id/eprint/59720/1/Wiley-20142015-01.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
https://orca.cardiff.ac.uk/id/eprint/59720/1/Wiley-20142015-01.pdf Barker, Stephen https://orca.cardiff.ac.uk/view/cardiffauthors/A015364W.html orcid:0000-0001-7870-6431 orcid:0000-0001-7870-6431 and Diz, Paula 2014. Timing of the descent into the last ice age determined by the bipolar seesaw. Paleoceanography 29 (6) , pp. 489-507. 10.1002/2014PA002623 https://doi.org/10.1002/2014PA002623 file https://orca.cardiff.ac.uk/59720/1/Wiley-20142015-01.pdf doi:10.1002/2014PA002623 |
op_rights |
cc_by |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1002/2014PA002623 |
container_title |
Paleoceanography |
container_volume |
29 |
container_issue |
6 |
container_start_page |
489 |
op_container_end_page |
507 |
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1766019130177093632 |