Younger Dryas ice margin retreat in Greenland:New evidence from southwestern Greenland
To date the final stage in deglaciation of the Greenland shelf, when a contiguous ice sheet margin on the inner shelf transitioned to outlet glaciers in troughs with intervening ice-free areas, we generated cosmogenic 10 Be dates from bedrock knobs on six outlying islands along a stretch of 300 km o...
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2021
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ftuniaarhuspubl:oai:pure.atira.dk:publications/3257ed5e-c45d-464a-83b8-9582c8f48457 2024-05-19T07:40:56+00:00 Younger Dryas ice margin retreat in Greenland:New evidence from southwestern Greenland Funder, Svend Sørensen, Anita H.L. Larsen, Nicolaj K. Bjørk, Anders A. Briner, Jason P. Olsen, Jesper Schomacker, Anders Levy, Laura B. Kjær, Kurt H. 2021-03 https://pure.au.dk/portal/en/publications/3257ed5e-c45d-464a-83b8-9582c8f48457 https://doi.org/10.5194/cp-17-587-2021 http://www.scopus.com/inward/record.url?scp=85102058117&partnerID=8YFLogxK eng eng https://pure.au.dk/portal/en/publications/3257ed5e-c45d-464a-83b8-9582c8f48457 info:eu-repo/semantics/openAccess Funder , S , Sørensen , A H L , Larsen , N K , Bjørk , A A , Briner , J P , Olsen , J , Schomacker , A , Levy , L B & Kjær , K H 2021 , ' Younger Dryas ice margin retreat in Greenland : New evidence from southwestern Greenland ' , Climate of the Past , vol. 17 , no. 2 , pp. 587-601 . https://doi.org/10.5194/cp-17-587-2021 article 2021 ftuniaarhuspubl https://doi.org/10.5194/cp-17-587-2021 2024-05-01T23:46:33Z To date the final stage in deglaciation of the Greenland shelf, when a contiguous ice sheet margin on the inner shelf transitioned to outlet glaciers in troughs with intervening ice-free areas, we generated cosmogenic 10 Be dates from bedrock knobs on six outlying islands along a stretch of 300 km of the southwestern Greenland coast. Despite 10 Be inheritance influencing some dates, the ages generally support a Greenland Ice Sheet (GrIS) margin that retreated off the inner shelf during the middle Younger Dryas (YD) period. Published 10 Be-and 14 C-dated records show that this history of the GrIS margin is seen in other parts of Greenland but with large variations in the extent and speed of retreat, sometimes even between neighbouring areas. Areas with a chronology extending into the Allerød period show no marked ice margin change at the Allerød-YD transition except in northernmost Greenland. In contrast, landforms on the shelf (moraines and grounding zone wedges) have been suggested to indicate YD readvances or long-lasting ice margin stillstands on the middle shelf. However, these features have been dated primarily by correlation with cold periods in the ice core temperature records. Ice margin retreat during the middle and late YD is explained by advection of warm subsurface water at the ice margin and by increased seasonality. Our results therefore point to the complexity of the climate-ice margin relation and to the urgent need for direct dating of the early deglaciation history of Greenland. Article in Journal/Newspaper Greenland ice core Ice Sheet Aarhus University: Research Climate of the Past 17 2 587 601 |
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Open Polar |
collection |
Aarhus University: Research |
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ftuniaarhuspubl |
language |
English |
description |
To date the final stage in deglaciation of the Greenland shelf, when a contiguous ice sheet margin on the inner shelf transitioned to outlet glaciers in troughs with intervening ice-free areas, we generated cosmogenic 10 Be dates from bedrock knobs on six outlying islands along a stretch of 300 km of the southwestern Greenland coast. Despite 10 Be inheritance influencing some dates, the ages generally support a Greenland Ice Sheet (GrIS) margin that retreated off the inner shelf during the middle Younger Dryas (YD) period. Published 10 Be-and 14 C-dated records show that this history of the GrIS margin is seen in other parts of Greenland but with large variations in the extent and speed of retreat, sometimes even between neighbouring areas. Areas with a chronology extending into the Allerød period show no marked ice margin change at the Allerød-YD transition except in northernmost Greenland. In contrast, landforms on the shelf (moraines and grounding zone wedges) have been suggested to indicate YD readvances or long-lasting ice margin stillstands on the middle shelf. However, these features have been dated primarily by correlation with cold periods in the ice core temperature records. Ice margin retreat during the middle and late YD is explained by advection of warm subsurface water at the ice margin and by increased seasonality. Our results therefore point to the complexity of the climate-ice margin relation and to the urgent need for direct dating of the early deglaciation history of Greenland. |
format |
Article in Journal/Newspaper |
author |
Funder, Svend Sørensen, Anita H.L. Larsen, Nicolaj K. Bjørk, Anders A. Briner, Jason P. Olsen, Jesper Schomacker, Anders Levy, Laura B. Kjær, Kurt H. |
spellingShingle |
Funder, Svend Sørensen, Anita H.L. Larsen, Nicolaj K. Bjørk, Anders A. Briner, Jason P. Olsen, Jesper Schomacker, Anders Levy, Laura B. Kjær, Kurt H. Younger Dryas ice margin retreat in Greenland:New evidence from southwestern Greenland |
author_facet |
Funder, Svend Sørensen, Anita H.L. Larsen, Nicolaj K. Bjørk, Anders A. Briner, Jason P. Olsen, Jesper Schomacker, Anders Levy, Laura B. Kjær, Kurt H. |
author_sort |
Funder, Svend |
title |
Younger Dryas ice margin retreat in Greenland:New evidence from southwestern Greenland |
title_short |
Younger Dryas ice margin retreat in Greenland:New evidence from southwestern Greenland |
title_full |
Younger Dryas ice margin retreat in Greenland:New evidence from southwestern Greenland |
title_fullStr |
Younger Dryas ice margin retreat in Greenland:New evidence from southwestern Greenland |
title_full_unstemmed |
Younger Dryas ice margin retreat in Greenland:New evidence from southwestern Greenland |
title_sort |
younger dryas ice margin retreat in greenland:new evidence from southwestern greenland |
publishDate |
2021 |
url |
https://pure.au.dk/portal/en/publications/3257ed5e-c45d-464a-83b8-9582c8f48457 https://doi.org/10.5194/cp-17-587-2021 http://www.scopus.com/inward/record.url?scp=85102058117&partnerID=8YFLogxK |
genre |
Greenland ice core Ice Sheet |
genre_facet |
Greenland ice core Ice Sheet |
op_source |
Funder , S , Sørensen , A H L , Larsen , N K , Bjørk , A A , Briner , J P , Olsen , J , Schomacker , A , Levy , L B & Kjær , K H 2021 , ' Younger Dryas ice margin retreat in Greenland : New evidence from southwestern Greenland ' , Climate of the Past , vol. 17 , no. 2 , pp. 587-601 . https://doi.org/10.5194/cp-17-587-2021 |
op_relation |
https://pure.au.dk/portal/en/publications/3257ed5e-c45d-464a-83b8-9582c8f48457 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/cp-17-587-2021 |
container_title |
Climate of the Past |
container_volume |
17 |
container_issue |
2 |
container_start_page |
587 |
op_container_end_page |
601 |
_version_ |
1799480497298997248 |