Reconstruction of east-west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years
International audience Radiogenic neodymium isotopes have been used as a water mass mixing proxy to investigate past changes in ocean circulation. Here we present a new depth transect of deglacial neodymium isotope records measured on uncleaned planktic foraminifera from five cores spanning from 330...
Published in: | Earth and Planetary Science Letters |
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Language: | English |
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ftunivlille:oai:HAL:insu-03664844v1 2024-06-23T07:54:51+00:00 Reconstruction of east-west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years Howe, Jacob N. W. Piotrowski, Alexander M. Hu, Rong Bory, Aloys Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG) Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Nord ) 2017 https://insu.hal.science/insu-03664844 https://insu.hal.science/insu-03664844/document https://insu.hal.science/insu-03664844/file/1-s2.0-S0012821X16306136-main.pdf https://doi.org/10.1016/j.epsl.2016.10.048 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2016.10.048 insu-03664844 https://insu.hal.science/insu-03664844 https://insu.hal.science/insu-03664844/document https://insu.hal.science/insu-03664844/file/1-s2.0-S0012821X16306136-main.pdf BIBCODE: 2017E&PSL.458.327H doi:10.1016/j.epsl.2016.10.048 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 0012-821X Earth and Planetary Science Letters https://insu.hal.science/insu-03664844 Earth and Planetary Science Letters, 2017, 458, pp.327-336. ⟨10.1016/j.epsl.2016.10.048⟩ neodymium isotopes Last Glacial Maximum eastern Atlantic western Atlantic [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2017 ftunivlille https://doi.org/10.1016/j.epsl.2016.10.048 2024-06-10T14:41:54Z International audience Radiogenic neodymium isotopes have been used as a water mass mixing proxy to investigate past changes in ocean circulation. Here we present a new depth transect of deglacial neodymium isotope records measured on uncleaned planktic foraminifera from five cores spanning from 3300 to 4900 m on the Mauritanian margin, in the tropical eastern Atlantic as well as an additional record from 4000 m on the Ceara Rise in the equatorial western Atlantic. Despite being located under the Saharan dust plume, the eastern Atlantic records differ from the composition of detrital inputs through time and exhibit similar values to the western Atlantic foraminiferal Nd across the deglaciation. Therefore we interpret the foraminiferal values as recording deep water Nd isotope changes. All six cores shift to less radiogenic values across the deglaciation, indicating that they were bathed by a lower proportion of North Atlantic Deep Water during the Last Glacial Maximum (LGM) relative to the Holocene. The eastern Atlantic records also show that a neodymium isotope gradient was present during the LGM and during the deglaciation, with more radiogenic values observed at the deepest sites. A homogeneous water mass observed below 3750 m in the deepest eastern Atlantic during the LGM is attributed to the mixing of deep water by rough topography as it passes from the western Atlantic through the fracture zones in the Mid-Atlantic Ridge. This implies that during the LGM the low latitude deep eastern Atlantic was ventilated from the western Atlantic via advection through fracture zones in the same manner as occurs in the modern ocean. Comparison with carbon isotopes indicates there was more respired carbon in the deep eastern than deep western Atlantic during the LGM, as is also seen in the modern Atlantic Ocean. Article in Journal/Newspaper North Atlantic Deep Water North Atlantic LillOA (HAL Lille Open Archive, Université de Lille) Mid-Atlantic Ridge Earth and Planetary Science Letters 458 327 336 |
institution |
Open Polar |
collection |
LillOA (HAL Lille Open Archive, Université de Lille) |
op_collection_id |
ftunivlille |
language |
English |
topic |
neodymium isotopes Last Glacial Maximum eastern Atlantic western Atlantic [SDU]Sciences of the Universe [physics] |
spellingShingle |
neodymium isotopes Last Glacial Maximum eastern Atlantic western Atlantic [SDU]Sciences of the Universe [physics] Howe, Jacob N. W. Piotrowski, Alexander M. Hu, Rong Bory, Aloys Reconstruction of east-west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years |
topic_facet |
neodymium isotopes Last Glacial Maximum eastern Atlantic western Atlantic [SDU]Sciences of the Universe [physics] |
description |
International audience Radiogenic neodymium isotopes have been used as a water mass mixing proxy to investigate past changes in ocean circulation. Here we present a new depth transect of deglacial neodymium isotope records measured on uncleaned planktic foraminifera from five cores spanning from 3300 to 4900 m on the Mauritanian margin, in the tropical eastern Atlantic as well as an additional record from 4000 m on the Ceara Rise in the equatorial western Atlantic. Despite being located under the Saharan dust plume, the eastern Atlantic records differ from the composition of detrital inputs through time and exhibit similar values to the western Atlantic foraminiferal Nd across the deglaciation. Therefore we interpret the foraminiferal values as recording deep water Nd isotope changes. All six cores shift to less radiogenic values across the deglaciation, indicating that they were bathed by a lower proportion of North Atlantic Deep Water during the Last Glacial Maximum (LGM) relative to the Holocene. The eastern Atlantic records also show that a neodymium isotope gradient was present during the LGM and during the deglaciation, with more radiogenic values observed at the deepest sites. A homogeneous water mass observed below 3750 m in the deepest eastern Atlantic during the LGM is attributed to the mixing of deep water by rough topography as it passes from the western Atlantic through the fracture zones in the Mid-Atlantic Ridge. This implies that during the LGM the low latitude deep eastern Atlantic was ventilated from the western Atlantic via advection through fracture zones in the same manner as occurs in the modern ocean. Comparison with carbon isotopes indicates there was more respired carbon in the deep eastern than deep western Atlantic during the LGM, as is also seen in the modern Atlantic Ocean. |
author2 |
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG) Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD France-Nord ) |
format |
Article in Journal/Newspaper |
author |
Howe, Jacob N. W. Piotrowski, Alexander M. Hu, Rong Bory, Aloys |
author_facet |
Howe, Jacob N. W. Piotrowski, Alexander M. Hu, Rong Bory, Aloys |
author_sort |
Howe, Jacob N. W. |
title |
Reconstruction of east-west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years |
title_short |
Reconstruction of east-west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years |
title_full |
Reconstruction of east-west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years |
title_fullStr |
Reconstruction of east-west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years |
title_full_unstemmed |
Reconstruction of east-west deep water exchange in the low latitude Atlantic Ocean over the past 25,000 years |
title_sort |
reconstruction of east-west deep water exchange in the low latitude atlantic ocean over the past 25,000 years |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://insu.hal.science/insu-03664844 https://insu.hal.science/insu-03664844/document https://insu.hal.science/insu-03664844/file/1-s2.0-S0012821X16306136-main.pdf https://doi.org/10.1016/j.epsl.2016.10.048 |
geographic |
Mid-Atlantic Ridge |
geographic_facet |
Mid-Atlantic Ridge |
genre |
North Atlantic Deep Water North Atlantic |
genre_facet |
North Atlantic Deep Water North Atlantic |
op_source |
ISSN: 0012-821X Earth and Planetary Science Letters https://insu.hal.science/insu-03664844 Earth and Planetary Science Letters, 2017, 458, pp.327-336. ⟨10.1016/j.epsl.2016.10.048⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.epsl.2016.10.048 insu-03664844 https://insu.hal.science/insu-03664844 https://insu.hal.science/insu-03664844/document https://insu.hal.science/insu-03664844/file/1-s2.0-S0012821X16306136-main.pdf BIBCODE: 2017E&PSL.458.327H doi:10.1016/j.epsl.2016.10.048 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1016/j.epsl.2016.10.048 |
container_title |
Earth and Planetary Science Letters |
container_volume |
458 |
container_start_page |
327 |
op_container_end_page |
336 |
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1802647152598450176 |