Organic geochemistry of sediment cores from the Arbian Sea, supplement to: Schulte, Sonja; Rostek, Frauke; Bard, Edouard; Rullkötter, Jürgen; Marchal, Olivier (1999): Variations of oxygen-minimum and primary productivity recorded in sediments of the Arabian Sea. Earth and Planetary Science Letters, 173(3), 205-221
Two deep-sea sediment cores from the northeastern and the southeastern Arabian Sea were studied in order to reconstruct the palaeoenvironments of the past glacial cycles. Core 136KL was recovered from the high-productivity area off Pakistan within the modern oxygen-minimum zone (OMZ). By contrast, m...
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ftdatacite:10.1594/pangaea.733514 2023-05-15T17:36:58+02:00 Organic geochemistry of sediment cores from the Arbian Sea, supplement to: Schulte, Sonja; Rostek, Frauke; Bard, Edouard; Rullkötter, Jürgen; Marchal, Olivier (1999): Variations of oxygen-minimum and primary productivity recorded in sediments of the Arabian Sea. Earth and Planetary Science Letters, 173(3), 205-221 Schulte, Sonja Rostek, Frauke Bard, Edouard Rullkötter, Jürgen Marchal, Olivier 1999 application/zip https://dx.doi.org/10.1594/pangaea.733514 https://doi.pangaea.de/10.1594/PANGAEA.733514 en eng PANGAEA - Data Publisher for Earth & Environmental Science https://dx.doi.org/10.1016/s0012-821x(99)00232-0 Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 CC-BY Piston corer Piston corer BGR type MD65 SO90 Marion Dufresne 1972 Sonne article Supplementary Collection of Datasets Collection 1999 ftdatacite https://doi.org/10.1594/pangaea.733514 https://doi.org/10.1016/s0012-821x(99)00232-0 2022-02-09T13:17:17Z Two deep-sea sediment cores from the northeastern and the southeastern Arabian Sea were studied in order to reconstruct the palaeoenvironments of the past glacial cycles. Core 136KL was recovered from the high-productivity area off Pakistan within the modern oxygen-minimum zone (OMZ). By contrast, modern primary productivity at the site of MD900963 close to Maldives is moderate and bottom waters are today well oxygenated. For both cores, we reconstructed the changes in palaeoproductivity using a set of biomarkers (alkenones, dinosterol and brassicasterol); the main result is that primary productivity is enhanced during glacial stages and lowered during interstadials. The proxies associated with productivity show a 23 kyr cyclicity corresponding to the precession-related insolation cycle. Palaeoredox conditions were studied in both cores using a new organic geochemical parameter (C35/C31-n-alkane ratio) developed by analysing surface sediments from a transect across the OMZ off Pakistan. The value of this ratio in core 136KL shows many variations during the last 65 kyr, indicating that the OMZ was not stable during this time: it disappeared completely during Heinrich- and the Younger Dryas events, pointing to a connection between global oceanic circulation and the stability of the OMZ. The C35/C31 ratio determined in sediments of core MD900963 shows that bottom waters remained rather well oxygenated over the last 330 kyr, which is confirmed by comparison with authigenic metal concentrations in the same sediments. A zonally averaged, circulation-biogeochemical ocean model was used to explore how the intermediate Indian Ocean responds to a freshwater flux anomaly at the surface of the North Atlantic. As suggested by the geochemical time series, both the abundance of Southern Ocean Water and the oxygen concentration are significantly increased in response to this freshwater perturbation. Article in Journal/Newspaper North Atlantic Southern Ocean DataCite Metadata Store (German National Library of Science and Technology) Indian Southern Ocean |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
Piston corer Piston corer BGR type MD65 SO90 Marion Dufresne 1972 Sonne |
spellingShingle |
Piston corer Piston corer BGR type MD65 SO90 Marion Dufresne 1972 Sonne Schulte, Sonja Rostek, Frauke Bard, Edouard Rullkötter, Jürgen Marchal, Olivier Organic geochemistry of sediment cores from the Arbian Sea, supplement to: Schulte, Sonja; Rostek, Frauke; Bard, Edouard; Rullkötter, Jürgen; Marchal, Olivier (1999): Variations of oxygen-minimum and primary productivity recorded in sediments of the Arabian Sea. Earth and Planetary Science Letters, 173(3), 205-221 |
topic_facet |
Piston corer Piston corer BGR type MD65 SO90 Marion Dufresne 1972 Sonne |
description |
Two deep-sea sediment cores from the northeastern and the southeastern Arabian Sea were studied in order to reconstruct the palaeoenvironments of the past glacial cycles. Core 136KL was recovered from the high-productivity area off Pakistan within the modern oxygen-minimum zone (OMZ). By contrast, modern primary productivity at the site of MD900963 close to Maldives is moderate and bottom waters are today well oxygenated. For both cores, we reconstructed the changes in palaeoproductivity using a set of biomarkers (alkenones, dinosterol and brassicasterol); the main result is that primary productivity is enhanced during glacial stages and lowered during interstadials. The proxies associated with productivity show a 23 kyr cyclicity corresponding to the precession-related insolation cycle. Palaeoredox conditions were studied in both cores using a new organic geochemical parameter (C35/C31-n-alkane ratio) developed by analysing surface sediments from a transect across the OMZ off Pakistan. The value of this ratio in core 136KL shows many variations during the last 65 kyr, indicating that the OMZ was not stable during this time: it disappeared completely during Heinrich- and the Younger Dryas events, pointing to a connection between global oceanic circulation and the stability of the OMZ. The C35/C31 ratio determined in sediments of core MD900963 shows that bottom waters remained rather well oxygenated over the last 330 kyr, which is confirmed by comparison with authigenic metal concentrations in the same sediments. A zonally averaged, circulation-biogeochemical ocean model was used to explore how the intermediate Indian Ocean responds to a freshwater flux anomaly at the surface of the North Atlantic. As suggested by the geochemical time series, both the abundance of Southern Ocean Water and the oxygen concentration are significantly increased in response to this freshwater perturbation. |
format |
Article in Journal/Newspaper |
author |
Schulte, Sonja Rostek, Frauke Bard, Edouard Rullkötter, Jürgen Marchal, Olivier |
author_facet |
Schulte, Sonja Rostek, Frauke Bard, Edouard Rullkötter, Jürgen Marchal, Olivier |
author_sort |
Schulte, Sonja |
title |
Organic geochemistry of sediment cores from the Arbian Sea, supplement to: Schulte, Sonja; Rostek, Frauke; Bard, Edouard; Rullkötter, Jürgen; Marchal, Olivier (1999): Variations of oxygen-minimum and primary productivity recorded in sediments of the Arabian Sea. Earth and Planetary Science Letters, 173(3), 205-221 |
title_short |
Organic geochemistry of sediment cores from the Arbian Sea, supplement to: Schulte, Sonja; Rostek, Frauke; Bard, Edouard; Rullkötter, Jürgen; Marchal, Olivier (1999): Variations of oxygen-minimum and primary productivity recorded in sediments of the Arabian Sea. Earth and Planetary Science Letters, 173(3), 205-221 |
title_full |
Organic geochemistry of sediment cores from the Arbian Sea, supplement to: Schulte, Sonja; Rostek, Frauke; Bard, Edouard; Rullkötter, Jürgen; Marchal, Olivier (1999): Variations of oxygen-minimum and primary productivity recorded in sediments of the Arabian Sea. Earth and Planetary Science Letters, 173(3), 205-221 |
title_fullStr |
Organic geochemistry of sediment cores from the Arbian Sea, supplement to: Schulte, Sonja; Rostek, Frauke; Bard, Edouard; Rullkötter, Jürgen; Marchal, Olivier (1999): Variations of oxygen-minimum and primary productivity recorded in sediments of the Arabian Sea. Earth and Planetary Science Letters, 173(3), 205-221 |
title_full_unstemmed |
Organic geochemistry of sediment cores from the Arbian Sea, supplement to: Schulte, Sonja; Rostek, Frauke; Bard, Edouard; Rullkötter, Jürgen; Marchal, Olivier (1999): Variations of oxygen-minimum and primary productivity recorded in sediments of the Arabian Sea. Earth and Planetary Science Letters, 173(3), 205-221 |
title_sort |
organic geochemistry of sediment cores from the arbian sea, supplement to: schulte, sonja; rostek, frauke; bard, edouard; rullkötter, jürgen; marchal, olivier (1999): variations of oxygen-minimum and primary productivity recorded in sediments of the arabian sea. earth and planetary science letters, 173(3), 205-221 |
publisher |
PANGAEA - Data Publisher for Earth & Environmental Science |
publishDate |
1999 |
url |
https://dx.doi.org/10.1594/pangaea.733514 https://doi.pangaea.de/10.1594/PANGAEA.733514 |
geographic |
Indian Southern Ocean |
geographic_facet |
Indian Southern Ocean |
genre |
North Atlantic Southern Ocean |
genre_facet |
North Atlantic Southern Ocean |
op_relation |
https://dx.doi.org/10.1016/s0012-821x(99)00232-0 |
op_rights |
Creative Commons Attribution 3.0 Unported https://creativecommons.org/licenses/by/3.0/legalcode cc-by-3.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/pangaea.733514 https://doi.org/10.1016/s0012-821x(99)00232-0 |
_version_ |
1766136630575366144 |