Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation
The onset of the North Atlantic Deep Water formation is thought to have coincided with Antarctic ice-sheet growth about 34 million years ago (Ma). However, this timing is debated, in part due to questions over the geochemical signature of the ancient Northern Component Water (NCW) formed in the deep...
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Online Access: | http://hdl.handle.net/10044/1/57836 https://doi.org/10.1038/s41561-018-0069-9 |
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/57836 2023-05-15T13:54:42+02:00 Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation Coxall, HK Huck, CE Huber, M Lear, CH Legarda-Lisarri, A O’Regan, M Sliwinska, KK Van de Flierdt, T De Boer, AM Zachos, JC Backman, J Natural Environment Research Council (NERC) Natural Environment Research Council (NERC) 2018-01-22 http://hdl.handle.net/10044/1/57836 https://doi.org/10.1038/s41561-018-0069-9 unknown Nature Publishing Group Nature Geoscience © 2018 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. 196 190 Science & Technology Physical Sciences Geosciences Multidisciplinary Geology MERIDIONAL OVERTURNING CIRCULATION FORAMINIFERAL MG/CA PALEOTHERMOMETRY SOUTHERN LABRADOR SEA THERMOHALINE CIRCULATION SECULAR VARIATION DRAKE PASSAGE ARCTIC-OCEAN ATLANTIC EOCENE EVOLUTION MD Multidisciplinary Meteorology & Atmospheric Sciences Journal Article 2018 ftimperialcol https://doi.org/10.1038/s41561-018-0069-9 2018-09-16T06:01:56Z The onset of the North Atlantic Deep Water formation is thought to have coincided with Antarctic ice-sheet growth about 34 million years ago (Ma). However, this timing is debated, in part due to questions over the geochemical signature of the ancient Northern Component Water (NCW) formed in the deep North Atlantic. Here we present detailed geochemical records from North Atlantic sediment cores located close to sites of deep-water formation. We find that prior to 36 Ma, the northwestern Atlantic was stratified, with nutrient-rich, low-salinity bottom waters. This restricted basin transitioned into a conduit for NCW that began flowing southwards approximately one million years before the initial Antarctic glaciation. The probable trigger was tectonic adjustments in subarctic seas that enabled an increased exchange across the Greenland–Scotland Ridge. The increasing surface salinity and density strengthened the production of NCW. The late Eocene deep-water mass differed in its carbon isotopic signature from modern values as a result of the leakage of fossil carbon from the Arctic Ocean. Export of this nutrient-laden water provided a transient pulse of CO2 to the Earth system, which perhaps caused short-term warming, whereas the long-term effect of enhanced NCW formation was a greater northward heat transport that cooled Antarctica. Article in Journal/Newspaper Antarc* Antarctic Antarctica Arctic Arctic Ocean Drake Passage Foraminifera* Greenland Greenland-Scotland Ridge Ice Sheet Labrador Sea North Atlantic Deep Water North Atlantic Subarctic Imperial College London: Spiral Antarctic Arctic Arctic Ocean Drake Passage Greenland Nature Geoscience 11 3 190 196 |
institution |
Open Polar |
collection |
Imperial College London: Spiral |
op_collection_id |
ftimperialcol |
language |
unknown |
topic |
Science & Technology Physical Sciences Geosciences Multidisciplinary Geology MERIDIONAL OVERTURNING CIRCULATION FORAMINIFERAL MG/CA PALEOTHERMOMETRY SOUTHERN LABRADOR SEA THERMOHALINE CIRCULATION SECULAR VARIATION DRAKE PASSAGE ARCTIC-OCEAN ATLANTIC EOCENE EVOLUTION MD Multidisciplinary Meteorology & Atmospheric Sciences |
spellingShingle |
Science & Technology Physical Sciences Geosciences Multidisciplinary Geology MERIDIONAL OVERTURNING CIRCULATION FORAMINIFERAL MG/CA PALEOTHERMOMETRY SOUTHERN LABRADOR SEA THERMOHALINE CIRCULATION SECULAR VARIATION DRAKE PASSAGE ARCTIC-OCEAN ATLANTIC EOCENE EVOLUTION MD Multidisciplinary Meteorology & Atmospheric Sciences Coxall, HK Huck, CE Huber, M Lear, CH Legarda-Lisarri, A O’Regan, M Sliwinska, KK Van de Flierdt, T De Boer, AM Zachos, JC Backman, J Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation |
topic_facet |
Science & Technology Physical Sciences Geosciences Multidisciplinary Geology MERIDIONAL OVERTURNING CIRCULATION FORAMINIFERAL MG/CA PALEOTHERMOMETRY SOUTHERN LABRADOR SEA THERMOHALINE CIRCULATION SECULAR VARIATION DRAKE PASSAGE ARCTIC-OCEAN ATLANTIC EOCENE EVOLUTION MD Multidisciplinary Meteorology & Atmospheric Sciences |
description |
The onset of the North Atlantic Deep Water formation is thought to have coincided with Antarctic ice-sheet growth about 34 million years ago (Ma). However, this timing is debated, in part due to questions over the geochemical signature of the ancient Northern Component Water (NCW) formed in the deep North Atlantic. Here we present detailed geochemical records from North Atlantic sediment cores located close to sites of deep-water formation. We find that prior to 36 Ma, the northwestern Atlantic was stratified, with nutrient-rich, low-salinity bottom waters. This restricted basin transitioned into a conduit for NCW that began flowing southwards approximately one million years before the initial Antarctic glaciation. The probable trigger was tectonic adjustments in subarctic seas that enabled an increased exchange across the Greenland–Scotland Ridge. The increasing surface salinity and density strengthened the production of NCW. The late Eocene deep-water mass differed in its carbon isotopic signature from modern values as a result of the leakage of fossil carbon from the Arctic Ocean. Export of this nutrient-laden water provided a transient pulse of CO2 to the Earth system, which perhaps caused short-term warming, whereas the long-term effect of enhanced NCW formation was a greater northward heat transport that cooled Antarctica. |
author2 |
Natural Environment Research Council (NERC) Natural Environment Research Council (NERC) |
format |
Article in Journal/Newspaper |
author |
Coxall, HK Huck, CE Huber, M Lear, CH Legarda-Lisarri, A O’Regan, M Sliwinska, KK Van de Flierdt, T De Boer, AM Zachos, JC Backman, J |
author_facet |
Coxall, HK Huck, CE Huber, M Lear, CH Legarda-Lisarri, A O’Regan, M Sliwinska, KK Van de Flierdt, T De Boer, AM Zachos, JC Backman, J |
author_sort |
Coxall, HK |
title |
Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation |
title_short |
Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation |
title_full |
Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation |
title_fullStr |
Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation |
title_full_unstemmed |
Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation |
title_sort |
export of nutrient rich northern component water preceded early oligocene antarctic glaciation |
publisher |
Nature Publishing Group |
publishDate |
2018 |
url |
http://hdl.handle.net/10044/1/57836 https://doi.org/10.1038/s41561-018-0069-9 |
geographic |
Antarctic Arctic Arctic Ocean Drake Passage Greenland |
geographic_facet |
Antarctic Arctic Arctic Ocean Drake Passage Greenland |
genre |
Antarc* Antarctic Antarctica Arctic Arctic Ocean Drake Passage Foraminifera* Greenland Greenland-Scotland Ridge Ice Sheet Labrador Sea North Atlantic Deep Water North Atlantic Subarctic |
genre_facet |
Antarc* Antarctic Antarctica Arctic Arctic Ocean Drake Passage Foraminifera* Greenland Greenland-Scotland Ridge Ice Sheet Labrador Sea North Atlantic Deep Water North Atlantic Subarctic |
op_source |
196 190 |
op_relation |
Nature Geoscience |
op_rights |
© 2018 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. |
op_doi |
https://doi.org/10.1038/s41561-018-0069-9 |
container_title |
Nature Geoscience |
container_volume |
11 |
container_issue |
3 |
container_start_page |
190 |
op_container_end_page |
196 |
_version_ |
1766260781318406144 |