Geochemical proxies of North American freshwater routing during the Younger Dryas cold event
The Younger Dryas cold interval represents a time when much of the Northern Hemisphere cooled from �12.9 to 11.5 kiloyears B.P. The cause of this event, which has long been viewed as the canonical example of abrupt climate change, was initially attributed to the routing of freshwater to the St. Lawr...
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National Academy of Sciences
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Online Access: | https://oceanrep.geomar.de/id/eprint/6040/ https://oceanrep.geomar.de/id/eprint/6040/1/Carlson_PNAS.pdf http://www.pnas.org/cgi/doi/10.1073/pnas.0611313104 https://doi.org/10.1073/pnas.0611313104 |
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ftoceanrep:oai:oceanrep.geomar.de:6040 2023-05-15T18:00:56+02:00 Geochemical proxies of North American freshwater routing during the Younger Dryas cold event Carlson, Anders E. Clark, Peter U. Haley, Brian Klinkhammer, Gary P. Simmons, Kathleen Brook, Edward J. Meissner, Katrin J. 2007 text https://oceanrep.geomar.de/id/eprint/6040/ https://oceanrep.geomar.de/id/eprint/6040/1/Carlson_PNAS.pdf http://www.pnas.org/cgi/doi/10.1073/pnas.0611313104 https://doi.org/10.1073/pnas.0611313104 en eng National Academy of Sciences https://oceanrep.geomar.de/id/eprint/6040/1/Carlson_PNAS.pdf Carlson, A. E., Clark, P. U., Haley, B., Klinkhammer, G. P., Simmons, K., Brook, E. J. and Meissner, K. J. (2007) Geochemical proxies of North American freshwater routing during the Younger Dryas cold event. PNAS Proceedings of the National Academy of Sciences of the United States of America, 104 . pp. 6556-6561. DOI 10.1073/pnas.0611313104 <https://doi.org/10.1073/pnas.0611313104>. doi:10.1073/pnas.0611313104 info:eu-repo/semantics/embargoedAccess Article PeerReviewed 2007 ftoceanrep https://doi.org/10.1073/pnas.0611313104 2023-04-07T14:52:11Z The Younger Dryas cold interval represents a time when much of the Northern Hemisphere cooled from �12.9 to 11.5 kiloyears B.P. The cause of this event, which has long been viewed as the canonical example of abrupt climate change, was initially attributed to the routing of freshwater to the St. Lawrence River with an attendant reduction in Atlantic meridional overturning circulation. However, this mechanism has recently been questioned because current proxies and dating techniques have been unable to confirm that eastward routing with an increase in freshwater flux occurred during the Younger Dryas. Here we use new geochemical proxies (�Mg/Ca, U/Ca, and 87Sr/86Sr) measured in planktonic foraminifera at the mouth of the St. Lawrence estuary as tracers of freshwater sources to further evaluate this question. Our proxies, combined with planktonic �18Oseawater and �13C, confirm that routing of runoff from western Canada to the St. Lawrence River occurred at the start of the Younger Dryas, with an attendant increase in freshwater flux of 0.06 +- 0.02 Sverdrup (1 Sverdrup = 106 m3s-1). This base discharge increase is sufficient to have reduced Atlantic meridional overturning circulation and caused the Younger Dryas cold interval. In addition, our data indicate subsequent fluctuations in the freshwater flux to the St. Lawrence River of ~0.06–0.12 Sverdrup, thus explaining the variability in the overturning circulation and climate during the Younger Dryas. Article in Journal/Newspaper Planktonic foraminifera OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Canada Lawrence River ENVELOPE(-115.002,-115.002,58.384,58.384) Proceedings of the National Academy of Sciences 104 16 6556 6561 |
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Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The Younger Dryas cold interval represents a time when much of the Northern Hemisphere cooled from �12.9 to 11.5 kiloyears B.P. The cause of this event, which has long been viewed as the canonical example of abrupt climate change, was initially attributed to the routing of freshwater to the St. Lawrence River with an attendant reduction in Atlantic meridional overturning circulation. However, this mechanism has recently been questioned because current proxies and dating techniques have been unable to confirm that eastward routing with an increase in freshwater flux occurred during the Younger Dryas. Here we use new geochemical proxies (�Mg/Ca, U/Ca, and 87Sr/86Sr) measured in planktonic foraminifera at the mouth of the St. Lawrence estuary as tracers of freshwater sources to further evaluate this question. Our proxies, combined with planktonic �18Oseawater and �13C, confirm that routing of runoff from western Canada to the St. Lawrence River occurred at the start of the Younger Dryas, with an attendant increase in freshwater flux of 0.06 +- 0.02 Sverdrup (1 Sverdrup = 106 m3s-1). This base discharge increase is sufficient to have reduced Atlantic meridional overturning circulation and caused the Younger Dryas cold interval. In addition, our data indicate subsequent fluctuations in the freshwater flux to the St. Lawrence River of ~0.06–0.12 Sverdrup, thus explaining the variability in the overturning circulation and climate during the Younger Dryas. |
format |
Article in Journal/Newspaper |
author |
Carlson, Anders E. Clark, Peter U. Haley, Brian Klinkhammer, Gary P. Simmons, Kathleen Brook, Edward J. Meissner, Katrin J. |
spellingShingle |
Carlson, Anders E. Clark, Peter U. Haley, Brian Klinkhammer, Gary P. Simmons, Kathleen Brook, Edward J. Meissner, Katrin J. Geochemical proxies of North American freshwater routing during the Younger Dryas cold event |
author_facet |
Carlson, Anders E. Clark, Peter U. Haley, Brian Klinkhammer, Gary P. Simmons, Kathleen Brook, Edward J. Meissner, Katrin J. |
author_sort |
Carlson, Anders E. |
title |
Geochemical proxies of North American freshwater routing during the Younger Dryas cold event |
title_short |
Geochemical proxies of North American freshwater routing during the Younger Dryas cold event |
title_full |
Geochemical proxies of North American freshwater routing during the Younger Dryas cold event |
title_fullStr |
Geochemical proxies of North American freshwater routing during the Younger Dryas cold event |
title_full_unstemmed |
Geochemical proxies of North American freshwater routing during the Younger Dryas cold event |
title_sort |
geochemical proxies of north american freshwater routing during the younger dryas cold event |
publisher |
National Academy of Sciences |
publishDate |
2007 |
url |
https://oceanrep.geomar.de/id/eprint/6040/ https://oceanrep.geomar.de/id/eprint/6040/1/Carlson_PNAS.pdf http://www.pnas.org/cgi/doi/10.1073/pnas.0611313104 https://doi.org/10.1073/pnas.0611313104 |
long_lat |
ENVELOPE(-115.002,-115.002,58.384,58.384) |
geographic |
Canada Lawrence River |
geographic_facet |
Canada Lawrence River |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_relation |
https://oceanrep.geomar.de/id/eprint/6040/1/Carlson_PNAS.pdf Carlson, A. E., Clark, P. U., Haley, B., Klinkhammer, G. P., Simmons, K., Brook, E. J. and Meissner, K. J. (2007) Geochemical proxies of North American freshwater routing during the Younger Dryas cold event. PNAS Proceedings of the National Academy of Sciences of the United States of America, 104 . pp. 6556-6561. DOI 10.1073/pnas.0611313104 <https://doi.org/10.1073/pnas.0611313104>. doi:10.1073/pnas.0611313104 |
op_rights |
info:eu-repo/semantics/embargoedAccess |
op_doi |
https://doi.org/10.1073/pnas.0611313104 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
104 |
container_issue |
16 |
container_start_page |
6556 |
op_container_end_page |
6561 |
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1766170223467036672 |