Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation
Establishing a time frame for the development of the modern halocline and stratified water column in the subarctic North Pacific has significant paleoclimatic implications. Here we present a δ18O(diatom) record consisting of only two species that represents autumn/winter conditions in the region acr...
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American Geophysical Union
2006
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Online Access: | http://nora.nerc.ac.uk/id/eprint/228/ http://www.agu.org/pubs/crossref/2006/2005PA001147.shtml https://doi.org/10.1029/2005PA001147 |
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ftnerc:oai:nora.nerc.ac.uk:228 2024-06-09T07:49:50+00:00 Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation Swann, George E. A. Maslin, Mark A. Leng, Melanie J. Sloane, Hilary J. Haug, Gerald H. 2006 http://nora.nerc.ac.uk/id/eprint/228/ http://www.agu.org/pubs/crossref/2006/2005PA001147.shtml https://doi.org/10.1029/2005PA001147 unknown American Geophysical Union Swann, George E. A.; Maslin, Mark A.; Leng, Melanie J. orcid:0000-0003-1115-5166 Sloane, Hilary J.; Haug, Gerald H. 2006 Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation. Paleoceanography, 21. PA1009. https://doi.org/10.1029/2005PA001147 <https://doi.org/10.1029/2005PA001147> Earth Sciences Publication - Article PeerReviewed 2006 ftnerc https://doi.org/10.1029/2005PA001147 2024-05-15T08:39:04Z Establishing a time frame for the development of the modern halocline and stratified water column in the subarctic North Pacific has significant paleoclimatic implications. Here we present a δ18O(diatom) record consisting of only two species that represents autumn/winter conditions in the region across the onset of major Northern Hemisphere glaciation boundary. At circa 2.73 Ma a decrease in δ18O(diatom) of 4.6‰ occurs, whereas previously published δ18O(foram) results show a 2.6‰ increase. The δ18O(diatom) and U37 k sea surface reconstructions indicate both a significant freshening of 2–4 practical salinity units and an increase in surface temperatures in the summer to early winter period from circa 2.73 Ma onward. In contrast, the concomitant increase in δ18O(foram) is likely to be reflective of conditions beneath the mesothermal structure and/or spring conditions when warmer sea surface temperatures are not present in the region. These results are consistent with the development of the modern halocline system at 2.73 Ma with year-round stratification of the water column and a strengthened seasonal thermocline during the summer to early winter period, resulting in one of the largest summer to winter temperature gradients in the open ocean. The onset of stratification would also have led to a warm pool of surface water from circa 2.73 Ma, which may have provided a potential source of extra moisture needed to supply the growing North American ice sheets at this time. Article in Journal/Newspaper Subarctic Natural Environment Research Council: NERC Open Research Archive Pacific Paleoceanography 21 1 n/a n/a |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Earth Sciences |
spellingShingle |
Earth Sciences Swann, George E. A. Maslin, Mark A. Leng, Melanie J. Sloane, Hilary J. Haug, Gerald H. Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation |
topic_facet |
Earth Sciences |
description |
Establishing a time frame for the development of the modern halocline and stratified water column in the subarctic North Pacific has significant paleoclimatic implications. Here we present a δ18O(diatom) record consisting of only two species that represents autumn/winter conditions in the region across the onset of major Northern Hemisphere glaciation boundary. At circa 2.73 Ma a decrease in δ18O(diatom) of 4.6‰ occurs, whereas previously published δ18O(foram) results show a 2.6‰ increase. The δ18O(diatom) and U37 k sea surface reconstructions indicate both a significant freshening of 2–4 practical salinity units and an increase in surface temperatures in the summer to early winter period from circa 2.73 Ma onward. In contrast, the concomitant increase in δ18O(foram) is likely to be reflective of conditions beneath the mesothermal structure and/or spring conditions when warmer sea surface temperatures are not present in the region. These results are consistent with the development of the modern halocline system at 2.73 Ma with year-round stratification of the water column and a strengthened seasonal thermocline during the summer to early winter period, resulting in one of the largest summer to winter temperature gradients in the open ocean. The onset of stratification would also have led to a warm pool of surface water from circa 2.73 Ma, which may have provided a potential source of extra moisture needed to supply the growing North American ice sheets at this time. |
format |
Article in Journal/Newspaper |
author |
Swann, George E. A. Maslin, Mark A. Leng, Melanie J. Sloane, Hilary J. Haug, Gerald H. |
author_facet |
Swann, George E. A. Maslin, Mark A. Leng, Melanie J. Sloane, Hilary J. Haug, Gerald H. |
author_sort |
Swann, George E. A. |
title |
Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation |
title_short |
Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation |
title_full |
Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation |
title_fullStr |
Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation |
title_full_unstemmed |
Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation |
title_sort |
diatom δ18o evidence for the development of the modern halocline system in the subarctic northwest pacific at the onset of major northern hemisphere glaciation |
publisher |
American Geophysical Union |
publishDate |
2006 |
url |
http://nora.nerc.ac.uk/id/eprint/228/ http://www.agu.org/pubs/crossref/2006/2005PA001147.shtml https://doi.org/10.1029/2005PA001147 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Subarctic |
genre_facet |
Subarctic |
op_relation |
Swann, George E. A.; Maslin, Mark A.; Leng, Melanie J. orcid:0000-0003-1115-5166 Sloane, Hilary J.; Haug, Gerald H. 2006 Diatom δ18O evidence for the development of the modern halocline system in the subarctic northwest Pacific at the onset of major Northern Hemisphere glaciation. Paleoceanography, 21. PA1009. https://doi.org/10.1029/2005PA001147 <https://doi.org/10.1029/2005PA001147> |
op_doi |
https://doi.org/10.1029/2005PA001147 |
container_title |
Paleoceanography |
container_volume |
21 |
container_issue |
1 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1801382699383914496 |