Early break-up of the Norwegian Channel Ice Stream during the Last Glacial Maximum
We present 18 new cosmogenic ¹⁰Be exposure ages that constrain the breakup time of the Norwegian Channel Ice Stream (NCIS) and the initial retreat of the Scandinavian Ice Sheet from the Southwest coast of Norway following the Last Glacial Maximum (LGM). Seven samples from glacially transported errat...
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ftdatacite:10.7916/d8p26xjj 2023-05-15T16:40:23+02:00 Early break-up of the Norwegian Channel Ice Stream during the Last Glacial Maximum Svendsen, John Inge Briner, Jason P. Mangerud, Jan Young, Nicolas E. 2015 https://dx.doi.org/10.7916/d8p26xjj https://academiccommons.columbia.edu/doi/10.7916/D8P26XJJ unknown Columbia University https://dx.doi.org/10.1016/j.quascirev.2014.11.001 Glaciers Cosmogenic nuclides Paleoclimatology Geochemistry Geomorphology Text Articles article-journal ScholarlyArticle 2015 ftdatacite https://doi.org/10.7916/d8p26xjj https://doi.org/10.1016/j.quascirev.2014.11.001 2021-11-05T12:55:41Z We present 18 new cosmogenic ¹⁰Be exposure ages that constrain the breakup time of the Norwegian Channel Ice Stream (NCIS) and the initial retreat of the Scandinavian Ice Sheet from the Southwest coast of Norway following the Last Glacial Maximum (LGM). Seven samples from glacially transported erratics on the island Utsira, located in the path of the NCIS about 400 km up-flow from the LGM ice front position, yielded an average ¹⁰Be age of 22.0 ± 2.0 ka. The distribution of the ages is skewed with the 4 youngest all within the range 20.2–20.8 ka. We place most confidence on this cluster of ages to constrain the timing of ice sheet retreat as we suspect the 3 oldest ages have some inheritance from a previous ice free period. Three additional ages from the adjacent island Karmøy provided an average age of 20.9 ± 0.7 ka, further supporting the new timing of retreat for the NCIS. The ¹⁰Be ages from Utsira and Karmøy suggest that the ice stream broke up about 2000 years earlier than the age assignment based on ¹⁴C ages on foraminifera and molluscs from marine sediment cores. We postulate that the Scandinavian Ice Sheet flowed across the Norwegian Channel to Denmark and onto the North Sea plateau during early phases of the LGM. When the NCIS started to operate this ice supply to the North Sea was cut off and the fast flow of the NCIS also led to a lowering of the ice surface along the Norwegian Channel and thereby drawdown of the entire ice sheet. This facilitated rapid calving of the ice front in the North Sea and we reconstruct a large open bay across the entire northern North Sea by ∼20 ka based on our ¹⁰Be ages in the east and radiocarbon ages from marine cores in the west. Additional ¹⁰Be ages show that the mainland slightly east of the islands Utsira and Karmøy remained ice covered until about 16 ka, indicating almost no net ice-margin retreat for the 4000 years between 20 and 16 ka. After 16 ka the ice margin retreated quickly up-fjord. Text Ice Sheet DataCite Metadata Store (German National Library of Science and Technology) Norway Utsira ENVELOPE(21.477,21.477,77.149,77.149) Open Bay ENVELOPE(-56.015,-56.015,51.583,51.583) |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
unknown |
topic |
Glaciers Cosmogenic nuclides Paleoclimatology Geochemistry Geomorphology |
spellingShingle |
Glaciers Cosmogenic nuclides Paleoclimatology Geochemistry Geomorphology Svendsen, John Inge Briner, Jason P. Mangerud, Jan Young, Nicolas E. Early break-up of the Norwegian Channel Ice Stream during the Last Glacial Maximum |
topic_facet |
Glaciers Cosmogenic nuclides Paleoclimatology Geochemistry Geomorphology |
description |
We present 18 new cosmogenic ¹⁰Be exposure ages that constrain the breakup time of the Norwegian Channel Ice Stream (NCIS) and the initial retreat of the Scandinavian Ice Sheet from the Southwest coast of Norway following the Last Glacial Maximum (LGM). Seven samples from glacially transported erratics on the island Utsira, located in the path of the NCIS about 400 km up-flow from the LGM ice front position, yielded an average ¹⁰Be age of 22.0 ± 2.0 ka. The distribution of the ages is skewed with the 4 youngest all within the range 20.2–20.8 ka. We place most confidence on this cluster of ages to constrain the timing of ice sheet retreat as we suspect the 3 oldest ages have some inheritance from a previous ice free period. Three additional ages from the adjacent island Karmøy provided an average age of 20.9 ± 0.7 ka, further supporting the new timing of retreat for the NCIS. The ¹⁰Be ages from Utsira and Karmøy suggest that the ice stream broke up about 2000 years earlier than the age assignment based on ¹⁴C ages on foraminifera and molluscs from marine sediment cores. We postulate that the Scandinavian Ice Sheet flowed across the Norwegian Channel to Denmark and onto the North Sea plateau during early phases of the LGM. When the NCIS started to operate this ice supply to the North Sea was cut off and the fast flow of the NCIS also led to a lowering of the ice surface along the Norwegian Channel and thereby drawdown of the entire ice sheet. This facilitated rapid calving of the ice front in the North Sea and we reconstruct a large open bay across the entire northern North Sea by ∼20 ka based on our ¹⁰Be ages in the east and radiocarbon ages from marine cores in the west. Additional ¹⁰Be ages show that the mainland slightly east of the islands Utsira and Karmøy remained ice covered until about 16 ka, indicating almost no net ice-margin retreat for the 4000 years between 20 and 16 ka. After 16 ka the ice margin retreated quickly up-fjord. |
format |
Text |
author |
Svendsen, John Inge Briner, Jason P. Mangerud, Jan Young, Nicolas E. |
author_facet |
Svendsen, John Inge Briner, Jason P. Mangerud, Jan Young, Nicolas E. |
author_sort |
Svendsen, John Inge |
title |
Early break-up of the Norwegian Channel Ice Stream during the Last Glacial Maximum |
title_short |
Early break-up of the Norwegian Channel Ice Stream during the Last Glacial Maximum |
title_full |
Early break-up of the Norwegian Channel Ice Stream during the Last Glacial Maximum |
title_fullStr |
Early break-up of the Norwegian Channel Ice Stream during the Last Glacial Maximum |
title_full_unstemmed |
Early break-up of the Norwegian Channel Ice Stream during the Last Glacial Maximum |
title_sort |
early break-up of the norwegian channel ice stream during the last glacial maximum |
publisher |
Columbia University |
publishDate |
2015 |
url |
https://dx.doi.org/10.7916/d8p26xjj https://academiccommons.columbia.edu/doi/10.7916/D8P26XJJ |
long_lat |
ENVELOPE(21.477,21.477,77.149,77.149) ENVELOPE(-56.015,-56.015,51.583,51.583) |
geographic |
Norway Utsira Open Bay |
geographic_facet |
Norway Utsira Open Bay |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
https://dx.doi.org/10.1016/j.quascirev.2014.11.001 |
op_doi |
https://doi.org/10.7916/d8p26xjj https://doi.org/10.1016/j.quascirev.2014.11.001 |
_version_ |
1766030769659052032 |