Glacial history of Inglefield Land, north Greenland from combined in situ 10Be and 14C exposure dating
Determining the sensitivity of the Greenland Ice Sheet (GrIS) to Holocene climate changes is a key prerequisite for understanding the future response of the ice sheet to global warming. In this study, we present new information on the Holocene glacial history of the GrIS in Inglefield Land, north Gr...
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Online Access: | https://doi.org/10.5194/cp-16-1999-2020 https://cp.copernicus.org/articles/16/1999/2020/ |
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ftcopernicus:oai:publications.copernicus.org:cp85470 2023-05-15T16:21:20+02:00 Glacial history of Inglefield Land, north Greenland from combined in situ 10Be and 14C exposure dating Søndergaard, Anne Sofie Larsen, Nicolaj Krog Steinemann, Olivia Olsen, Jesper Funder, Svend Egholm, David Lundbek Kjær, Kurt Henrik 2020-10-30 application/pdf https://doi.org/10.5194/cp-16-1999-2020 https://cp.copernicus.org/articles/16/1999/2020/ eng eng doi:10.5194/cp-16-1999-2020 https://cp.copernicus.org/articles/16/1999/2020/ eISSN: 1814-9332 Text 2020 ftcopernicus https://doi.org/10.5194/cp-16-1999-2020 2020-11-02T17:22:13Z Determining the sensitivity of the Greenland Ice Sheet (GrIS) to Holocene climate changes is a key prerequisite for understanding the future response of the ice sheet to global warming. In this study, we present new information on the Holocene glacial history of the GrIS in Inglefield Land, north Greenland. We use 10 Be and in situ 14 C exposure dating to constrain the timing of deglaciation in the area and radiocarbon dating of reworked molluscs and wood fragments to constrain when the ice sheet retreated behind its present-day extent. The 10 Be ages are scattered ranging from ca. 92.7 to 6.8 ka, whereas the in situ 14 C ages range from ca. 14.2 to 6.7 ka. Almost half of the apparent 10 Be ages predate the Last Glacial Maximum and up to 89 % are to some degree affected by nuclide inheritance. Based on the few reliable 10 Be ages, the in situ 14 C ages and existing radiocarbon ages from Inglefield Land, we find that the deglaciation along the coast commenced at ca. 8.6–8.3 ka cal BP in the western part and ca. 7.9 ka in the central part, following the opening of Nares Strait and arrival of warm waters. The ice margin reached its present-day position at ca. 8.2 ka at the Humboldt Glacier and ca. 6.7 ka in the central part of Inglefield Land. Radiocarbon ages of reworked molluscs and wood fragments show that the ice margin was behind its present-day extent from ca. 5.8 to 0.5 ka cal BP. After 0.5 ka cal BP, the ice advanced towards its Little Ice Age position. Our results emphasize that the slowly eroding and possibly cold-based ice in north Greenland makes it difficult to constrain the deglaciation history based on 10 Be ages alone unless they are paired with in situ 14 C ages. Further, combining our findings with those of recently published studies reveals distinct differences between deglaciation patterns of northwest and north Greenland. Deglaciation of the land areas in northwest Greenland occurred earlier than in north Greenland, and periods of restricted ice extent were longer, spanning the Middle and Late Holocene. Overall, this highlights past ice sheet sensitivity to Holocene climate changes in an area where little information was available just a few years ago. Text glacier Greenland Humboldt Glacier Ice Sheet Inglefield land Nares strait North Greenland Copernicus Publications: E-Journals Greenland Inglefield Land ENVELOPE(-69.987,-69.987,78.637,78.637) Nares ENVELOPE(158.167,158.167,-81.450,-81.450) Climate of the Past 16 5 1999 2015 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
Determining the sensitivity of the Greenland Ice Sheet (GrIS) to Holocene climate changes is a key prerequisite for understanding the future response of the ice sheet to global warming. In this study, we present new information on the Holocene glacial history of the GrIS in Inglefield Land, north Greenland. We use 10 Be and in situ 14 C exposure dating to constrain the timing of deglaciation in the area and radiocarbon dating of reworked molluscs and wood fragments to constrain when the ice sheet retreated behind its present-day extent. The 10 Be ages are scattered ranging from ca. 92.7 to 6.8 ka, whereas the in situ 14 C ages range from ca. 14.2 to 6.7 ka. Almost half of the apparent 10 Be ages predate the Last Glacial Maximum and up to 89 % are to some degree affected by nuclide inheritance. Based on the few reliable 10 Be ages, the in situ 14 C ages and existing radiocarbon ages from Inglefield Land, we find that the deglaciation along the coast commenced at ca. 8.6–8.3 ka cal BP in the western part and ca. 7.9 ka in the central part, following the opening of Nares Strait and arrival of warm waters. The ice margin reached its present-day position at ca. 8.2 ka at the Humboldt Glacier and ca. 6.7 ka in the central part of Inglefield Land. Radiocarbon ages of reworked molluscs and wood fragments show that the ice margin was behind its present-day extent from ca. 5.8 to 0.5 ka cal BP. After 0.5 ka cal BP, the ice advanced towards its Little Ice Age position. Our results emphasize that the slowly eroding and possibly cold-based ice in north Greenland makes it difficult to constrain the deglaciation history based on 10 Be ages alone unless they are paired with in situ 14 C ages. Further, combining our findings with those of recently published studies reveals distinct differences between deglaciation patterns of northwest and north Greenland. Deglaciation of the land areas in northwest Greenland occurred earlier than in north Greenland, and periods of restricted ice extent were longer, spanning the Middle and Late Holocene. Overall, this highlights past ice sheet sensitivity to Holocene climate changes in an area where little information was available just a few years ago. |
format |
Text |
author |
Søndergaard, Anne Sofie Larsen, Nicolaj Krog Steinemann, Olivia Olsen, Jesper Funder, Svend Egholm, David Lundbek Kjær, Kurt Henrik |
spellingShingle |
Søndergaard, Anne Sofie Larsen, Nicolaj Krog Steinemann, Olivia Olsen, Jesper Funder, Svend Egholm, David Lundbek Kjær, Kurt Henrik Glacial history of Inglefield Land, north Greenland from combined in situ 10Be and 14C exposure dating |
author_facet |
Søndergaard, Anne Sofie Larsen, Nicolaj Krog Steinemann, Olivia Olsen, Jesper Funder, Svend Egholm, David Lundbek Kjær, Kurt Henrik |
author_sort |
Søndergaard, Anne Sofie |
title |
Glacial history of Inglefield Land, north Greenland from combined in situ 10Be and 14C exposure dating |
title_short |
Glacial history of Inglefield Land, north Greenland from combined in situ 10Be and 14C exposure dating |
title_full |
Glacial history of Inglefield Land, north Greenland from combined in situ 10Be and 14C exposure dating |
title_fullStr |
Glacial history of Inglefield Land, north Greenland from combined in situ 10Be and 14C exposure dating |
title_full_unstemmed |
Glacial history of Inglefield Land, north Greenland from combined in situ 10Be and 14C exposure dating |
title_sort |
glacial history of inglefield land, north greenland from combined in situ 10be and 14c exposure dating |
publishDate |
2020 |
url |
https://doi.org/10.5194/cp-16-1999-2020 https://cp.copernicus.org/articles/16/1999/2020/ |
long_lat |
ENVELOPE(-69.987,-69.987,78.637,78.637) ENVELOPE(158.167,158.167,-81.450,-81.450) |
geographic |
Greenland Inglefield Land Nares |
geographic_facet |
Greenland Inglefield Land Nares |
genre |
glacier Greenland Humboldt Glacier Ice Sheet Inglefield land Nares strait North Greenland |
genre_facet |
glacier Greenland Humboldt Glacier Ice Sheet Inglefield land Nares strait North Greenland |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-16-1999-2020 https://cp.copernicus.org/articles/16/1999/2020/ |
op_doi |
https://doi.org/10.5194/cp-16-1999-2020 |
container_title |
Climate of the Past |
container_volume |
16 |
container_issue |
5 |
container_start_page |
1999 |
op_container_end_page |
2015 |
_version_ |
1766009349348524032 |