Glacial expansion of carbon-rich deep waters into the Southwestern Indian Ocean over the last 630 kyr
Oceanic carbon storage is one of the main sinks for atmospheric CO2, and thought to be the major contributing factor for CO2 drawdown during past glacial periods. Both physical and biogeochemical processes control the capacity of carbon storage in the ocean. During glacial periods of the Pleistocene...
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Online Access: | https://hal.science/hal-04384155 https://doi.org/10.1016/j.gloplacha.2023.104283 |
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ftunivbrest:oai:HAL:hal-04384155v1 2024-02-11T10:08:33+01:00 Glacial expansion of carbon-rich deep waters into the Southwestern Indian Ocean over the last 630 kyr Pérez-Asensio, José N. Tachikawa, Kazuyo Vidal, Laurence de Garidel-Thoron, Thibault Sonzogni, Corinne Guihou, Abel Deschamps, Pierre Jorry, Stephan Chen, Min-Te Geo-Ocean (GEO-OCEAN) Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) 2023-11 https://hal.science/hal-04384155 https://doi.org/10.1016/j.gloplacha.2023.104283 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.gloplacha.2023.104283 hal-04384155 https://hal.science/hal-04384155 doi:10.1016/j.gloplacha.2023.104283 ISSN: 0921-8181 Global and Planetary Change https://hal.science/hal-04384155 Global and Planetary Change, 2023, 230, 104283 (13p.). ⟨10.1016/j.gloplacha.2023.104283⟩ [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2023 ftunivbrest https://doi.org/10.1016/j.gloplacha.2023.104283 2024-01-16T23:36:11Z Oceanic carbon storage is one of the main sinks for atmospheric CO2, and thought to be the major contributing factor for CO2 drawdown during past glacial periods. Both physical and biogeochemical processes control the capacity of carbon storage in the ocean. During glacial periods of the Pleistocene the larger volume of deep-water masses of Southern Hemisphere origin in the Atlantic has been shown to promote carbon storage in the Southern Ocean. However, the latitudinal extension of this water mass in the Indian Ocean has been scarcely studied. In this study, we combine foraminiferal εNd and benthic δ13C of two sediment cores in the southwest Indian Ocean (MD96–2077, 33°S, 3781 m water depth; MD96–2052, 19°S, 2627 m water depth), to reconstruct the spatial and temporal evolution of glacial carbon-rich deep waters in the SW Indian over the last 630 kyr. The combined use of foraminiferal εNd and benthic δ13C allows to distinguish δ13C changes related to water mass mixing and from respired carbon accumulation within the water masses. Nutrient-rich deep waters, which cannot be explained by the enhanced proportion of southern-sourced waters, were present at core sites deeper than 2700 m during glacial periods and extended at least until 33°S into the SW Indian Ocean. From Marine Isotope Stage (MIS) 14 to MIS 10, glacial carbon storage increased gradually until reaching its highest capacity during the extreme glacial periods MIS 12 and 10. Orbital forcing (100-kyr eccentricity, 41-kyr obliquity), restricted air-sea exchange and enhanced ocean stratification, fostered higher carbon storage during periods of relatively lower eccentricity and obliquity. Furthermore, after MIS 10, a progressive transition was observed from 100-kyr eccentricity to 41-kyr obliquity cycles in benthic δ13C and δ18O records of core MD96–2077 and sea-ice cover changes derived from ice-rafted debris of the Agulhas Plateau composite core site. Article in Journal/Newspaper Sea ice Southern Ocean Université de Bretagne Occidentale: HAL Southern Ocean Indian Global and Planetary Change 230 104283 |
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Open Polar |
collection |
Université de Bretagne Occidentale: HAL |
op_collection_id |
ftunivbrest |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Pérez-Asensio, José N. Tachikawa, Kazuyo Vidal, Laurence de Garidel-Thoron, Thibault Sonzogni, Corinne Guihou, Abel Deschamps, Pierre Jorry, Stephan Chen, Min-Te Glacial expansion of carbon-rich deep waters into the Southwestern Indian Ocean over the last 630 kyr |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
Oceanic carbon storage is one of the main sinks for atmospheric CO2, and thought to be the major contributing factor for CO2 drawdown during past glacial periods. Both physical and biogeochemical processes control the capacity of carbon storage in the ocean. During glacial periods of the Pleistocene the larger volume of deep-water masses of Southern Hemisphere origin in the Atlantic has been shown to promote carbon storage in the Southern Ocean. However, the latitudinal extension of this water mass in the Indian Ocean has been scarcely studied. In this study, we combine foraminiferal εNd and benthic δ13C of two sediment cores in the southwest Indian Ocean (MD96–2077, 33°S, 3781 m water depth; MD96–2052, 19°S, 2627 m water depth), to reconstruct the spatial and temporal evolution of glacial carbon-rich deep waters in the SW Indian over the last 630 kyr. The combined use of foraminiferal εNd and benthic δ13C allows to distinguish δ13C changes related to water mass mixing and from respired carbon accumulation within the water masses. Nutrient-rich deep waters, which cannot be explained by the enhanced proportion of southern-sourced waters, were present at core sites deeper than 2700 m during glacial periods and extended at least until 33°S into the SW Indian Ocean. From Marine Isotope Stage (MIS) 14 to MIS 10, glacial carbon storage increased gradually until reaching its highest capacity during the extreme glacial periods MIS 12 and 10. Orbital forcing (100-kyr eccentricity, 41-kyr obliquity), restricted air-sea exchange and enhanced ocean stratification, fostered higher carbon storage during periods of relatively lower eccentricity and obliquity. Furthermore, after MIS 10, a progressive transition was observed from 100-kyr eccentricity to 41-kyr obliquity cycles in benthic δ13C and δ18O records of core MD96–2077 and sea-ice cover changes derived from ice-rafted debris of the Agulhas Plateau composite core site. |
author2 |
Geo-Ocean (GEO-OCEAN) Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Pérez-Asensio, José N. Tachikawa, Kazuyo Vidal, Laurence de Garidel-Thoron, Thibault Sonzogni, Corinne Guihou, Abel Deschamps, Pierre Jorry, Stephan Chen, Min-Te |
author_facet |
Pérez-Asensio, José N. Tachikawa, Kazuyo Vidal, Laurence de Garidel-Thoron, Thibault Sonzogni, Corinne Guihou, Abel Deschamps, Pierre Jorry, Stephan Chen, Min-Te |
author_sort |
Pérez-Asensio, José N. |
title |
Glacial expansion of carbon-rich deep waters into the Southwestern Indian Ocean over the last 630 kyr |
title_short |
Glacial expansion of carbon-rich deep waters into the Southwestern Indian Ocean over the last 630 kyr |
title_full |
Glacial expansion of carbon-rich deep waters into the Southwestern Indian Ocean over the last 630 kyr |
title_fullStr |
Glacial expansion of carbon-rich deep waters into the Southwestern Indian Ocean over the last 630 kyr |
title_full_unstemmed |
Glacial expansion of carbon-rich deep waters into the Southwestern Indian Ocean over the last 630 kyr |
title_sort |
glacial expansion of carbon-rich deep waters into the southwestern indian ocean over the last 630 kyr |
publisher |
HAL CCSD |
publishDate |
2023 |
url |
https://hal.science/hal-04384155 https://doi.org/10.1016/j.gloplacha.2023.104283 |
geographic |
Southern Ocean Indian |
geographic_facet |
Southern Ocean Indian |
genre |
Sea ice Southern Ocean |
genre_facet |
Sea ice Southern Ocean |
op_source |
ISSN: 0921-8181 Global and Planetary Change https://hal.science/hal-04384155 Global and Planetary Change, 2023, 230, 104283 (13p.). ⟨10.1016/j.gloplacha.2023.104283⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.gloplacha.2023.104283 hal-04384155 https://hal.science/hal-04384155 doi:10.1016/j.gloplacha.2023.104283 |
op_doi |
https://doi.org/10.1016/j.gloplacha.2023.104283 |
container_title |
Global and Planetary Change |
container_volume |
230 |
container_start_page |
104283 |
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1790607941659787264 |