Surface and deep-water variability on the southern Agulhas Plateau: Interhemispheric links over the past 2 Ma
AGU's Fall Meeting 2019, in San Francisco (EE.UU.) 9–13 December 2019 The Southern Ocean is involved in setting the state of global climate through its role in redistributing heat and salt through the world ocean and its control on atmospheric CO2. Utilising sediment core sites on the southern...
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ftcsic:oai:digital.csic.es:10261/208815 2024-02-11T09:55:42+01:00 Surface and deep-water variability on the southern Agulhas Plateau: Interhemispheric links over the past 2 Ma Hall, Ian R. Starr, Aidan Hemming, Sidney R. Barker, Stephen Van Der Lubber, Jeroen Cartagena Sierra, Alejandra Berke, Melissa A. Gruetzner, Jens Jiménez Espejo, Francisco J. LeVay, Leah J. Lathika, Nambiyathodi Robinson, Rebecca S. 2019-12-09 http://hdl.handle.net/10261/208815 unknown Sí AGU Fall Meeting (2019) http://hdl.handle.net/10261/208815 none comunicación de congreso http://purl.org/coar/resource_type/c_5794 2019 ftcsic 2024-01-16T10:52:38Z AGU's Fall Meeting 2019, in San Francisco (EE.UU.) 9–13 December 2019 The Southern Ocean is involved in setting the state of global climate through its role in redistributing heat and salt through the world ocean and its control on atmospheric CO2. Utilising sediment core sites on the southern Agulhas Plateau (AP) in the southwest Indian Ocean, we present new records of ice-rafted debris mass accumulation rate (IRDMAR), intermediate and benthic oxygen and carbon isotope, sortable silt mean grain size and bulk sediment chemistry (XRF) spanning the past 2 Ma. The AP is situated at the southern extent of the Indian-Atlantic Ocean Gateway (I-AOG); the upper water column is dominated by Indian Ocean waters not leaked into the South Atlantic and instead flowing eastward as the Agulhas Return Current. South of the AP, the relatively cold and fresh waters of the Sub-Antarctic Zone (SAZ) meet their northern limit and steep meridional property gradients occur. The AP region is therefore highly sensitive to variations in both the Sub-Antarctic Zone (SAZ) to the south and the Agulhas Current System to the north. IODP Site U1475 (41°25.61¿S; 25°15.64¿E, 2669 m water depth), was recovered from a contourite drift deposit on the southern AP, situated close to the modern-day subtropical front. Together with complementary data from sediment core MD02-2588 from the same location, our results indicate that during glacial periods there was a persistent influence of a well-ventilated water mass within the I-AOG with a carbon isotope signature similar to present-day Northern Component Water (NCW). The records of chemical ventilation and near-bottom flow vigour closely reflect changes in the advection of NCW and meridional variability in the location of the Antarctic Circumpolar Current and its associated fronts, as recorded by IRDMAR. We suggest that equatorward expansions of the circum-Antarctic frontal system, occurring relatively early in the glacial sequence, are central in triggering this glacial overturning circulation, hence ... Conference Object Antarc* Antarctic Southern Ocean Digital.CSIC (Spanish National Research Council) Antarctic Indian Southern Ocean The Antarctic |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
unknown |
description |
AGU's Fall Meeting 2019, in San Francisco (EE.UU.) 9–13 December 2019 The Southern Ocean is involved in setting the state of global climate through its role in redistributing heat and salt through the world ocean and its control on atmospheric CO2. Utilising sediment core sites on the southern Agulhas Plateau (AP) in the southwest Indian Ocean, we present new records of ice-rafted debris mass accumulation rate (IRDMAR), intermediate and benthic oxygen and carbon isotope, sortable silt mean grain size and bulk sediment chemistry (XRF) spanning the past 2 Ma. The AP is situated at the southern extent of the Indian-Atlantic Ocean Gateway (I-AOG); the upper water column is dominated by Indian Ocean waters not leaked into the South Atlantic and instead flowing eastward as the Agulhas Return Current. South of the AP, the relatively cold and fresh waters of the Sub-Antarctic Zone (SAZ) meet their northern limit and steep meridional property gradients occur. The AP region is therefore highly sensitive to variations in both the Sub-Antarctic Zone (SAZ) to the south and the Agulhas Current System to the north. IODP Site U1475 (41°25.61¿S; 25°15.64¿E, 2669 m water depth), was recovered from a contourite drift deposit on the southern AP, situated close to the modern-day subtropical front. Together with complementary data from sediment core MD02-2588 from the same location, our results indicate that during glacial periods there was a persistent influence of a well-ventilated water mass within the I-AOG with a carbon isotope signature similar to present-day Northern Component Water (NCW). The records of chemical ventilation and near-bottom flow vigour closely reflect changes in the advection of NCW and meridional variability in the location of the Antarctic Circumpolar Current and its associated fronts, as recorded by IRDMAR. We suggest that equatorward expansions of the circum-Antarctic frontal system, occurring relatively early in the glacial sequence, are central in triggering this glacial overturning circulation, hence ... |
format |
Conference Object |
author |
Hall, Ian R. Starr, Aidan Hemming, Sidney R. Barker, Stephen Van Der Lubber, Jeroen Cartagena Sierra, Alejandra Berke, Melissa A. Gruetzner, Jens Jiménez Espejo, Francisco J. LeVay, Leah J. Lathika, Nambiyathodi Robinson, Rebecca S. |
spellingShingle |
Hall, Ian R. Starr, Aidan Hemming, Sidney R. Barker, Stephen Van Der Lubber, Jeroen Cartagena Sierra, Alejandra Berke, Melissa A. Gruetzner, Jens Jiménez Espejo, Francisco J. LeVay, Leah J. Lathika, Nambiyathodi Robinson, Rebecca S. Surface and deep-water variability on the southern Agulhas Plateau: Interhemispheric links over the past 2 Ma |
author_facet |
Hall, Ian R. Starr, Aidan Hemming, Sidney R. Barker, Stephen Van Der Lubber, Jeroen Cartagena Sierra, Alejandra Berke, Melissa A. Gruetzner, Jens Jiménez Espejo, Francisco J. LeVay, Leah J. Lathika, Nambiyathodi Robinson, Rebecca S. |
author_sort |
Hall, Ian R. |
title |
Surface and deep-water variability on the southern Agulhas Plateau: Interhemispheric links over the past 2 Ma |
title_short |
Surface and deep-water variability on the southern Agulhas Plateau: Interhemispheric links over the past 2 Ma |
title_full |
Surface and deep-water variability on the southern Agulhas Plateau: Interhemispheric links over the past 2 Ma |
title_fullStr |
Surface and deep-water variability on the southern Agulhas Plateau: Interhemispheric links over the past 2 Ma |
title_full_unstemmed |
Surface and deep-water variability on the southern Agulhas Plateau: Interhemispheric links over the past 2 Ma |
title_sort |
surface and deep-water variability on the southern agulhas plateau: interhemispheric links over the past 2 ma |
publishDate |
2019 |
url |
http://hdl.handle.net/10261/208815 |
geographic |
Antarctic Indian Southern Ocean The Antarctic |
geographic_facet |
Antarctic Indian Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
Sí AGU Fall Meeting (2019) http://hdl.handle.net/10261/208815 |
op_rights |
none |
_version_ |
1790598391503257600 |