Deep water variability on the southern Agulhas Plateau:
[1] 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...
Other Authors: | |
---|---|
Format: | Text |
Language: | English |
Subjects: | |
Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.463.6870 http://folk.uib.no/abo007/share/papers/eemian_and_lgi/molyneux_hall07.pao.pdf |
id |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.463.6870 |
---|---|
record_format |
openpolar |
spelling |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.463.6870 2023-05-15T13:51:38+02:00 Deep water variability on the southern Agulhas Plateau: The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.463.6870 http://folk.uib.no/abo007/share/papers/eemian_and_lgi/molyneux_hall07.pao.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.463.6870 http://folk.uib.no/abo007/share/papers/eemian_and_lgi/molyneux_hall07.pao.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://folk.uib.no/abo007/share/papers/eemian_and_lgi/molyneux_hall07.pao.pdf Indian and South Atlantic Oceans off South Africa [de text ftciteseerx 2016-01-08T06:46:35Z [1] 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 d13C 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 d13C of other Southern Ocean records but not in our benthic d13C 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 |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
ftciteseerx |
language |
English |
topic |
Indian and South Atlantic Oceans off South Africa [de |
spellingShingle |
Indian and South Atlantic Oceans off South Africa [de Deep water variability on the southern Agulhas Plateau: |
topic_facet |
Indian and South Atlantic Oceans off South Africa [de |
description |
[1] 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 d13C 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 d13C of other Southern Ocean records but not in our benthic d13C 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. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
title |
Deep water variability on the southern Agulhas Plateau: |
title_short |
Deep water variability on the southern Agulhas Plateau: |
title_full |
Deep water variability on the southern Agulhas Plateau: |
title_fullStr |
Deep water variability on the southern Agulhas Plateau: |
title_full_unstemmed |
Deep water variability on the southern Agulhas Plateau: |
title_sort |
deep water variability on the southern agulhas plateau: |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.463.6870 http://folk.uib.no/abo007/share/papers/eemian_and_lgi/molyneux_hall07.pao.pdf |
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 |
http://folk.uib.no/abo007/share/papers/eemian_and_lgi/molyneux_hall07.pao.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.463.6870 http://folk.uib.no/abo007/share/papers/eemian_and_lgi/molyneux_hall07.pao.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766255603341066240 |