Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions
International audience Using 95 epibenthic/5•3C records, eight time slices were reconstructed to trace the distribution of east Atlantic deepwater and intermediate water masses over the last 30,000 years. Our results show that there have been three distinct modes of deepwater circulation: Near the s...
Published in: | Paleoceanography |
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Main Authors: | , , , , , , |
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Format: | Article in Journal/Newspaper |
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1994
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Online Access: | https://hal.science/hal-03610638 https://hal.science/hal-03610638/document https://hal.science/hal-03610638/file/Paleoceanography%20-%20April%201994%20-%20Sarnthein%20-%20Changes%20in%20East%20Atlantic%20Deepwater%20Circulation%20over%20the%20last%2030%20000%20years%20.pdf https://doi.org/10.1029/93PA03301 |
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ftceafr:oai:HAL:hal-03610638v1 2024-09-15T17:44:14+00:00 Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions Sarnthein, Michael Winn, Kyaw Jung, Simon Duplessy, Jean-Claude Labeyrie, Laurent Erlenkeuser, Helmut Ganssen, Gerald Christian-Albrechts-Universität zu Kiel = Christian-Albrechts University of Kiel = Université Christian-Albrechts de Kiel (CAU) Centre des Faibles Radioactivités Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS) Vrije Universiteit Brussel Bruxelles (VUB) 1994-04 https://hal.science/hal-03610638 https://hal.science/hal-03610638/document https://hal.science/hal-03610638/file/Paleoceanography%20-%20April%201994%20-%20Sarnthein%20-%20Changes%20in%20East%20Atlantic%20Deepwater%20Circulation%20over%20the%20last%2030%20000%20years%20.pdf https://doi.org/10.1029/93PA03301 en eng HAL CCSD American Geophysical Union info:eu-repo/semantics/altIdentifier/doi/10.1029/93PA03301 hal-03610638 https://hal.science/hal-03610638 https://hal.science/hal-03610638/document https://hal.science/hal-03610638/file/Paleoceanography%20-%20April%201994%20-%20Sarnthein%20-%20Changes%20in%20East%20Atlantic%20Deepwater%20Circulation%20over%20the%20last%2030%20000%20years%20.pdf doi:10.1029/93PA03301 info:eu-repo/semantics/OpenAccess ISSN: 0883-8305 Paleoceanography https://hal.science/hal-03610638 Paleoceanography, 1994, 9 (2), pp.209-267. ⟨10.1029/93PA03301⟩ [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment info:eu-repo/semantics/article Journal articles 1994 ftceafr https://doi.org/10.1029/93PA03301 2024-07-22T13:12:06Z International audience Using 95 epibenthic/5•3C records, eight time slices were reconstructed to trace the distribution of east Atlantic deepwater and intermediate water masses over the last 30,000 years. Our results show that there have been three distinct modes of deepwater circulation: Near the stage 3-2 boundary, the origin of North Atlantic Deep Water (NADW) was similar to today (mode 1). However, after late stage 3 the source region of the NADW end-member shifted from the Norwegian-Greenland Sea to areas south of Iceland (mode 2). A reduced NADW flow persisted during the last glacial maximum, with constant preformed/5•3C values. The nutrient content of NADW increased markedly near the Azores fracture zone from north to south, probably because of the mixing of upwelled Antarctic Bottom Water (AABW) from below, which then advected with much higher flux rates into the northeast Atlantic. Later, the spread of glacial meltwater over the North Atlantic led to a marked short-term ventilation minimum below 1800 rn about 13,500 •C years ago (mode 3). The formation of NADW recommenced abruptly north of Iceland 12,800-12,500 years ago and reached a volume approaching that of the Holocene, in the Younger Dryas (10,800-10,350 years B.P.). Another short-term shutdown of deepwater formation followed between 10,200 and 9,600 years B.P., linked to a further major meltwater pulse into the Atlantic. Each renewal of deepwater formation led to a marked release of fossil CO2 from the ocean, the likely cause of the contemporaneous •4C plateaus. Over the last 9000 years, deepwater circulation varied little from today, apart from a slight increase in AABW about 7000 •4C years ago. It is also shown that the oxygenated Mediterranean outflow varied largely independent of the variations in deepwater circulation over the last 30,000 years. Article in Journal/Newspaper Antarc* Antarctic Greenland Greenland Sea Iceland NADW North Atlantic Deep Water North Atlantic Northeast Atlantic HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives) Paleoceanography 9 2 209 267 |
institution |
Open Polar |
collection |
HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives) |
op_collection_id |
ftceafr |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment Sarnthein, Michael Winn, Kyaw Jung, Simon Duplessy, Jean-Claude Labeyrie, Laurent Erlenkeuser, Helmut Ganssen, Gerald Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
description |
International audience Using 95 epibenthic/5•3C records, eight time slices were reconstructed to trace the distribution of east Atlantic deepwater and intermediate water masses over the last 30,000 years. Our results show that there have been three distinct modes of deepwater circulation: Near the stage 3-2 boundary, the origin of North Atlantic Deep Water (NADW) was similar to today (mode 1). However, after late stage 3 the source region of the NADW end-member shifted from the Norwegian-Greenland Sea to areas south of Iceland (mode 2). A reduced NADW flow persisted during the last glacial maximum, with constant preformed/5•3C values. The nutrient content of NADW increased markedly near the Azores fracture zone from north to south, probably because of the mixing of upwelled Antarctic Bottom Water (AABW) from below, which then advected with much higher flux rates into the northeast Atlantic. Later, the spread of glacial meltwater over the North Atlantic led to a marked short-term ventilation minimum below 1800 rn about 13,500 •C years ago (mode 3). The formation of NADW recommenced abruptly north of Iceland 12,800-12,500 years ago and reached a volume approaching that of the Holocene, in the Younger Dryas (10,800-10,350 years B.P.). Another short-term shutdown of deepwater formation followed between 10,200 and 9,600 years B.P., linked to a further major meltwater pulse into the Atlantic. Each renewal of deepwater formation led to a marked release of fossil CO2 from the ocean, the likely cause of the contemporaneous •4C plateaus. Over the last 9000 years, deepwater circulation varied little from today, apart from a slight increase in AABW about 7000 •4C years ago. It is also shown that the oxygenated Mediterranean outflow varied largely independent of the variations in deepwater circulation over the last 30,000 years. |
author2 |
Christian-Albrechts-Universität zu Kiel = Christian-Albrechts University of Kiel = Université Christian-Albrechts de Kiel (CAU) Centre des Faibles Radioactivités Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS) Vrije Universiteit Brussel Bruxelles (VUB) |
format |
Article in Journal/Newspaper |
author |
Sarnthein, Michael Winn, Kyaw Jung, Simon Duplessy, Jean-Claude Labeyrie, Laurent Erlenkeuser, Helmut Ganssen, Gerald |
author_facet |
Sarnthein, Michael Winn, Kyaw Jung, Simon Duplessy, Jean-Claude Labeyrie, Laurent Erlenkeuser, Helmut Ganssen, Gerald |
author_sort |
Sarnthein, Michael |
title |
Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions |
title_short |
Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions |
title_full |
Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions |
title_fullStr |
Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions |
title_full_unstemmed |
Changes in East Atlantic Deepwater Circulation over the last 30,000 years: Eight time slice reconstructions |
title_sort |
changes in east atlantic deepwater circulation over the last 30,000 years: eight time slice reconstructions |
publisher |
HAL CCSD |
publishDate |
1994 |
url |
https://hal.science/hal-03610638 https://hal.science/hal-03610638/document https://hal.science/hal-03610638/file/Paleoceanography%20-%20April%201994%20-%20Sarnthein%20-%20Changes%20in%20East%20Atlantic%20Deepwater%20Circulation%20over%20the%20last%2030%20000%20years%20.pdf https://doi.org/10.1029/93PA03301 |
genre |
Antarc* Antarctic Greenland Greenland Sea Iceland NADW North Atlantic Deep Water North Atlantic Northeast Atlantic |
genre_facet |
Antarc* Antarctic Greenland Greenland Sea Iceland NADW North Atlantic Deep Water North Atlantic Northeast Atlantic |
op_source |
ISSN: 0883-8305 Paleoceanography https://hal.science/hal-03610638 Paleoceanography, 1994, 9 (2), pp.209-267. ⟨10.1029/93PA03301⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1029/93PA03301 hal-03610638 https://hal.science/hal-03610638 https://hal.science/hal-03610638/document https://hal.science/hal-03610638/file/Paleoceanography%20-%20April%201994%20-%20Sarnthein%20-%20Changes%20in%20East%20Atlantic%20Deepwater%20Circulation%20over%20the%20last%2030%20000%20years%20.pdf doi:10.1029/93PA03301 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1029/93PA03301 |
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Paleoceanography |
container_volume |
9 |
container_issue |
2 |
container_start_page |
209 |
op_container_end_page |
267 |
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1810491654219497472 |