Deep water variability on the southern Agulhas Plateau: Interhemispheric links over the past 170 ka
Sortable silt mean grain sizes together with oxygen and carbon isotopic data produced on the benthic foraminiferal species Fontbotia wuellerstorfi are used to construct high-resolution records of near-bottom flow vigour and deep water ventilation at a core site MD02-2589 located at 2660 m water dept...
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Online Access: | https://doi.org/10.1029/2006PA001407 https://archimer.ifremer.fr/doc/00233/34459/32867.pdf https://archimer.ifremer.fr/doc/00233/34459/ |
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fttriple:oai:gotriple.eu:10670/1.j6ho8y 2023-05-15T13:38:44+02:00 Deep water variability on the southern Agulhas Plateau: Interhemispheric links over the past 170 ka Molyneux, Elizabeth G. Hall, Ian R. Zahn, Rainer Diz, Paula 2007-01-01 https://doi.org/10.1029/2006PA001407 https://archimer.ifremer.fr/doc/00233/34459/32867.pdf https://archimer.ifremer.fr/doc/00233/34459/ en eng Amer Geophysical Union doi:10.1029/2006PA001407 10670/1.j6ho8y https://archimer.ifremer.fr/doc/00233/34459/32867.pdf https://archimer.ifremer.fr/doc/00233/34459/ other Archimer, archive institutionnelle de l'Ifremer Paleoceanography (0883-8305) (Amer Geophysical Union), 2007-11 , Vol. 22 , N. 4/PA4209 , P. 1-14 envir geo Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2007 fttriple https://doi.org/10.1029/2006PA001407 2023-01-22T17:10:52Z Sortable silt mean grain sizes together with oxygen and carbon isotopic data produced on the benthic foraminiferal species Fontbotia wuellerstorfi are used to construct high-resolution records of near-bottom flow vigour and deep water ventilation at a core site MD02-2589 located at 2660 m water depth on the southern Agulhas Plateau. The results suggest that during glacial periods ( marine oxygen isotope stages 2 and 6, MIS 2 and MIS 6, respectively), there was a persistent contribution of a well-ventilated water mass within the Atlantic to Indian oceanic gateway with a delta(13)C signature similar to present-day Northern Component Water (NCW), e. g., North Atlantic Deep Water (NADW). The records of chemical ventilation and near-bottom flow vigor reflect changes in the advection of northern source waters and meridional variability in the location of the Antarctic Circumpolar Current and its associated fronts. We suggest that during Termination II (TII), changes in chemical ventilation are largely decoupled from near-bottom physical flow speeds. A mid-TII climate optimum is associated with a low-flow speed plateau concurrent with a period of increased ventilation shown in the benthic delta(13)C of other Southern Ocean records but not in our benthic delta(13)C of MD02-2589. The climate optimum is followed by a period of southern cooling around 128 ka coincident with a stronger influence of NCW to interglacial levels at around 124 ka. All proxy records show a near synchronous and rapid shift during the transition from MIS 5a-4 (73 ka). This large event is attributed to a rapid decrease in NADW influence and replacement over the Agulhas Plateau by southern source waters. Text Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic Southern Ocean Unknown Antarctic Indian Southern Ocean The Antarctic Paleoceanography 22 4 n/a n/a |
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envir geo Molyneux, Elizabeth G. Hall, Ian R. Zahn, Rainer Diz, Paula Deep water variability on the southern Agulhas Plateau: Interhemispheric links over the past 170 ka |
topic_facet |
envir geo |
description |
Sortable silt mean grain sizes together with oxygen and carbon isotopic data produced on the benthic foraminiferal species Fontbotia wuellerstorfi are used to construct high-resolution records of near-bottom flow vigour and deep water ventilation at a core site MD02-2589 located at 2660 m water depth on the southern Agulhas Plateau. The results suggest that during glacial periods ( marine oxygen isotope stages 2 and 6, MIS 2 and MIS 6, respectively), there was a persistent contribution of a well-ventilated water mass within the Atlantic to Indian oceanic gateway with a delta(13)C signature similar to present-day Northern Component Water (NCW), e. g., North Atlantic Deep Water (NADW). The records of chemical ventilation and near-bottom flow vigor reflect changes in the advection of northern source waters and meridional variability in the location of the Antarctic Circumpolar Current and its associated fronts. We suggest that during Termination II (TII), changes in chemical ventilation are largely decoupled from near-bottom physical flow speeds. A mid-TII climate optimum is associated with a low-flow speed plateau concurrent with a period of increased ventilation shown in the benthic delta(13)C of other Southern Ocean records but not in our benthic delta(13)C of MD02-2589. The climate optimum is followed by a period of southern cooling around 128 ka coincident with a stronger influence of NCW to interglacial levels at around 124 ka. All proxy records show a near synchronous and rapid shift during the transition from MIS 5a-4 (73 ka). This large event is attributed to a rapid decrease in NADW influence and replacement over the Agulhas Plateau by southern source waters. |
format |
Text |
author |
Molyneux, Elizabeth G. Hall, Ian R. Zahn, Rainer Diz, Paula |
author_facet |
Molyneux, Elizabeth G. Hall, Ian R. Zahn, Rainer Diz, Paula |
author_sort |
Molyneux, Elizabeth G. |
title |
Deep water variability on the southern Agulhas Plateau: Interhemispheric links over the past 170 ka |
title_short |
Deep water variability on the southern Agulhas Plateau: Interhemispheric links over the past 170 ka |
title_full |
Deep water variability on the southern Agulhas Plateau: Interhemispheric links over the past 170 ka |
title_fullStr |
Deep water variability on the southern Agulhas Plateau: Interhemispheric links over the past 170 ka |
title_full_unstemmed |
Deep water variability on the southern Agulhas Plateau: Interhemispheric links over the past 170 ka |
title_sort |
deep water variability on the southern agulhas plateau: interhemispheric links over the past 170 ka |
publisher |
Amer Geophysical Union |
publishDate |
2007 |
url |
https://doi.org/10.1029/2006PA001407 https://archimer.ifremer.fr/doc/00233/34459/32867.pdf https://archimer.ifremer.fr/doc/00233/34459/ |
geographic |
Antarctic Indian Southern Ocean The Antarctic |
geographic_facet |
Antarctic Indian Southern Ocean The Antarctic |
genre |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic NADW North Atlantic Deep Water North Atlantic Southern Ocean |
op_source |
Archimer, archive institutionnelle de l'Ifremer Paleoceanography (0883-8305) (Amer Geophysical Union), 2007-11 , Vol. 22 , N. 4/PA4209 , P. 1-14 |
op_relation |
doi:10.1029/2006PA001407 10670/1.j6ho8y https://archimer.ifremer.fr/doc/00233/34459/32867.pdf https://archimer.ifremer.fr/doc/00233/34459/ |
op_rights |
other |
op_doi |
https://doi.org/10.1029/2006PA001407 |
container_title |
Paleoceanography |
container_volume |
22 |
container_issue |
4 |
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n/a |
op_container_end_page |
n/a |
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1766110541180305408 |