Annual layering in the NGRIP ice core during the Eemian
The Greenland NGRIP ice core continuously covers the period from present day back to 123 ka before present, which includes several thousand years of ice from the previous interglacial period, MIS 5e or the Eemian. In the glacial part of the core, annual layers can be identified from impurity records...
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Copernicus Publications
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Online Access: | https://doi.org/10.5194/cp-7-1427-2011 http://www.clim-past.net/7/1427/2011/cp-7-1427-2011.pdf https://doaj.org/article/37835358d8624f87a1a23ad93a91e021 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:37835358d8624f87a1a23ad93a91e021 2023-05-15T16:30:03+02:00 Annual layering in the NGRIP ice core during the Eemian A. Svensson M. Bigler E. Kettner D. Dahl-Jensen S. Johnsen S. Kipfstuhl M. Nielsen J. P. Steffensen 2011-12-01 https://doi.org/10.5194/cp-7-1427-2011 http://www.clim-past.net/7/1427/2011/cp-7-1427-2011.pdf https://doaj.org/article/37835358d8624f87a1a23ad93a91e021 en eng Copernicus Publications doi:10.5194/cp-7-1427-2011 1814-9324 1814-9332 http://www.clim-past.net/7/1427/2011/cp-7-1427-2011.pdf https://doaj.org/article/37835358d8624f87a1a23ad93a91e021 undefined Climate of the Past, Vol 7, Iss 4, Pp 1427-1437 (2011) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2011 fttriple https://doi.org/10.5194/cp-7-1427-2011 2023-01-22T18:11:45Z The Greenland NGRIP ice core continuously covers the period from present day back to 123 ka before present, which includes several thousand years of ice from the previous interglacial period, MIS 5e or the Eemian. In the glacial part of the core, annual layers can be identified from impurity records and visual stratigraphy, and stratigraphic layer counting has been performed back to 60 ka. In the deepest part of the core, however, the ice is close to the pressure melting point, the visual stratigraphy is dominated by crystal boundaries, and annual layering is not visible to the naked eye. In this study, we apply a newly developed setup for high-resolution ice core impurity analysis to produce continuous records of dust, sodium and ammonium concentrations as well as conductivity of melt water. We analyzed three 2.2 m sections of ice from the Eemian and the glacial inception. In all of the analyzed ice, annual layers can clearly be recognized, most prominently in the dust and conductivity profiles. Part of the samples is, however, contaminated in dust, most likely from drill liquid. It is interesting that the annual layering is preserved despite a very active crystal growth and grain boundary migration in the deep and warm NGRIP ice. Based on annual layer counting of the new records, we determine a mean annual layer thickness close to 11 mm for all three sections, which, to first order, confirms the modeled NGRIP time scale (ss09sea). The counting does, however, suggest a longer duration of the climatically warmest part of the NGRIP record (MIS5e) of up to 1 ka as compared to the model estimate. Our results suggest that stratigraphic layer counting is possible basically throughout the entire NGRIP ice core, provided sufficiently highly-resolved profiles become available. Article in Journal/Newspaper Greenland ice core NGRIP Unknown Greenland Climate of the Past 7 4 1427 1437 |
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Open Polar |
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fttriple |
language |
English |
topic |
envir geo |
spellingShingle |
envir geo A. Svensson M. Bigler E. Kettner D. Dahl-Jensen S. Johnsen S. Kipfstuhl M. Nielsen J. P. Steffensen Annual layering in the NGRIP ice core during the Eemian |
topic_facet |
envir geo |
description |
The Greenland NGRIP ice core continuously covers the period from present day back to 123 ka before present, which includes several thousand years of ice from the previous interglacial period, MIS 5e or the Eemian. In the glacial part of the core, annual layers can be identified from impurity records and visual stratigraphy, and stratigraphic layer counting has been performed back to 60 ka. In the deepest part of the core, however, the ice is close to the pressure melting point, the visual stratigraphy is dominated by crystal boundaries, and annual layering is not visible to the naked eye. In this study, we apply a newly developed setup for high-resolution ice core impurity analysis to produce continuous records of dust, sodium and ammonium concentrations as well as conductivity of melt water. We analyzed three 2.2 m sections of ice from the Eemian and the glacial inception. In all of the analyzed ice, annual layers can clearly be recognized, most prominently in the dust and conductivity profiles. Part of the samples is, however, contaminated in dust, most likely from drill liquid. It is interesting that the annual layering is preserved despite a very active crystal growth and grain boundary migration in the deep and warm NGRIP ice. Based on annual layer counting of the new records, we determine a mean annual layer thickness close to 11 mm for all three sections, which, to first order, confirms the modeled NGRIP time scale (ss09sea). The counting does, however, suggest a longer duration of the climatically warmest part of the NGRIP record (MIS5e) of up to 1 ka as compared to the model estimate. Our results suggest that stratigraphic layer counting is possible basically throughout the entire NGRIP ice core, provided sufficiently highly-resolved profiles become available. |
format |
Article in Journal/Newspaper |
author |
A. Svensson M. Bigler E. Kettner D. Dahl-Jensen S. Johnsen S. Kipfstuhl M. Nielsen J. P. Steffensen |
author_facet |
A. Svensson M. Bigler E. Kettner D. Dahl-Jensen S. Johnsen S. Kipfstuhl M. Nielsen J. P. Steffensen |
author_sort |
A. Svensson |
title |
Annual layering in the NGRIP ice core during the Eemian |
title_short |
Annual layering in the NGRIP ice core during the Eemian |
title_full |
Annual layering in the NGRIP ice core during the Eemian |
title_fullStr |
Annual layering in the NGRIP ice core during the Eemian |
title_full_unstemmed |
Annual layering in the NGRIP ice core during the Eemian |
title_sort |
annual layering in the ngrip ice core during the eemian |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
https://doi.org/10.5194/cp-7-1427-2011 http://www.clim-past.net/7/1427/2011/cp-7-1427-2011.pdf https://doaj.org/article/37835358d8624f87a1a23ad93a91e021 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland ice core NGRIP |
genre_facet |
Greenland ice core NGRIP |
op_source |
Climate of the Past, Vol 7, Iss 4, Pp 1427-1437 (2011) |
op_relation |
doi:10.5194/cp-7-1427-2011 1814-9324 1814-9332 http://www.clim-past.net/7/1427/2011/cp-7-1427-2011.pdf https://doaj.org/article/37835358d8624f87a1a23ad93a91e021 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-7-1427-2011 |
container_title |
Climate of the Past |
container_volume |
7 |
container_issue |
4 |
container_start_page |
1427 |
op_container_end_page |
1437 |
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