The deglacial history of 79N glacier and the Northeast Greenland Ice Stream
The Northeast Greenland Ice Stream (NEGIS) is the main artery for ice discharge from the northeast sector of the Greenland Ice Sheet (GrIS) to the North Atlantic. Understanding the past, present and future stability of the NEGIS with respect to atmospheric and oceanic forcing is of global importance...
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2024
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Online Access: | https://research.manchester.ac.uk/en/publications/75d83eff-0528-4640-a8e5-76d4c9a22a0b https://doi.org/10.1016/j.quascirev.2024.108770 |
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ftumanchesterpub:oai:pure.atira.dk:publications/75d83eff-0528-4640-a8e5-76d4c9a22a0b 2024-09-15T17:43:05+00:00 The deglacial history of 79N glacier and the Northeast Greenland Ice Stream Roberts, David Lane, Timothy Jones, Richard Bentley, Michael Darvill, Christopher Rodes, Angel Smith, James Jamieson, Stewart Rea, Brice Fabel , Derek Gheorghiu, Delia M. Davidson, Allan Cofaigh, Colm Ó Lloyd, Jerry m. Callard, S. louise Humbert, Angelika 2024-07-15 https://research.manchester.ac.uk/en/publications/75d83eff-0528-4640-a8e5-76d4c9a22a0b https://doi.org/10.1016/j.quascirev.2024.108770 eng eng https://research.manchester.ac.uk/en/publications/75d83eff-0528-4640-a8e5-76d4c9a22a0b info:eu-repo/semantics/openAccess Roberts , D , Lane , T , Jones , R , Bentley , M , Darvill , C , Rodes , A , Smith , J , Jamieson , S , Rea , B , Fabel , D , Gheorghiu , D M , Davidson , A , Cofaigh , C Ó , Lloyd , J M , Callard , S L & Humbert , A 2024 , ' The deglacial history of 79N glacier and the Northeast Greenland Ice Stream ' , Quaternary Science Reviews , vol. 336 , 108770 . https://doi.org/10.1016/j.quascirev.2024.108770 Northeast Greenland Ice Stream Deglaciation Thinning history article 2024 ftumanchesterpub https://doi.org/10.1016/j.quascirev.2024.108770 2024-07-15T23:34:19Z The Northeast Greenland Ice Stream (NEGIS) is the main artery for ice discharge from the northeast sector of the Greenland Ice Sheet (GrIS) to the North Atlantic. Understanding the past, present and future stability of the NEGIS with respect to atmospheric and oceanic forcing is of global importance as it drains around 17% of the GrIS and has a sea-level equivalent of 1.6 m. This paper reconstructs the deglacial and Holocene history of Nioghalvfjerdsbræ (or 79N Glacier); a major outlet of the NEGIS. At high elevation (>900 m asl) autochthonous blockfield, a lack of glacially moulded bedrock and pre LGM exposure ages point to a complex exposure/burial history extending back over half a million years. However, post Marine Isotope Stage 12, enhanced glacial erosion led to fjord incision and plateaux abandonment. Between 900 and 600 m asl the terrain is largely unmodified by glacial scour but post LGM erratics indicate the advection of cold-based ice through the fjord. In contrast, below ∼600 m asl Nioghalvfjerdsfjorden exhibits a geomorphological signal indicative of a warm-based ice stream operating during the last glacial cycle. Dated ice marginal landforms and terrain along the fjord walls show initial thinning rates were slow between ∼23 and 10 ka, but post-10 ka it is evident that Nioghalvfjerdsfjorden deglaciated extremely quickly with complete fjord deglaciation below ∼500 m asl between 10.0 and 8.5 ka. Both increasing air and ocean temperatures were pivotal in driving surface lowering and submarine melt during deglaciation, but the final withdrawal of ice through Nioghalvfjerdsfjorden was facilitated by the action of marine ice sheet instability. Our estimates show that thinning and retreat rates reached a maximum of 5.29 ma −1 and 613 ma −1 , respectively, as the ice margin withdrew westwards. This would place the Early Holocene disintegration of this outlet of the NEGIS at the upper bounds of contemporary thinning and retreat rates seen both in Greenland and Antarctica. Combined with recent evidence of ... Article in Journal/Newspaper Antarc* Antarctica glacier Greenland Ice Sheet Nioghalvfjerdsfjorden North Atlantic The University of Manchester: Research Explorer Quaternary Science Reviews 336 108770 |
institution |
Open Polar |
collection |
The University of Manchester: Research Explorer |
op_collection_id |
ftumanchesterpub |
language |
English |
topic |
Northeast Greenland Ice Stream Deglaciation Thinning history |
spellingShingle |
Northeast Greenland Ice Stream Deglaciation Thinning history Roberts, David Lane, Timothy Jones, Richard Bentley, Michael Darvill, Christopher Rodes, Angel Smith, James Jamieson, Stewart Rea, Brice Fabel , Derek Gheorghiu, Delia M. Davidson, Allan Cofaigh, Colm Ó Lloyd, Jerry m. Callard, S. louise Humbert, Angelika The deglacial history of 79N glacier and the Northeast Greenland Ice Stream |
topic_facet |
Northeast Greenland Ice Stream Deglaciation Thinning history |
description |
The Northeast Greenland Ice Stream (NEGIS) is the main artery for ice discharge from the northeast sector of the Greenland Ice Sheet (GrIS) to the North Atlantic. Understanding the past, present and future stability of the NEGIS with respect to atmospheric and oceanic forcing is of global importance as it drains around 17% of the GrIS and has a sea-level equivalent of 1.6 m. This paper reconstructs the deglacial and Holocene history of Nioghalvfjerdsbræ (or 79N Glacier); a major outlet of the NEGIS. At high elevation (>900 m asl) autochthonous blockfield, a lack of glacially moulded bedrock and pre LGM exposure ages point to a complex exposure/burial history extending back over half a million years. However, post Marine Isotope Stage 12, enhanced glacial erosion led to fjord incision and plateaux abandonment. Between 900 and 600 m asl the terrain is largely unmodified by glacial scour but post LGM erratics indicate the advection of cold-based ice through the fjord. In contrast, below ∼600 m asl Nioghalvfjerdsfjorden exhibits a geomorphological signal indicative of a warm-based ice stream operating during the last glacial cycle. Dated ice marginal landforms and terrain along the fjord walls show initial thinning rates were slow between ∼23 and 10 ka, but post-10 ka it is evident that Nioghalvfjerdsfjorden deglaciated extremely quickly with complete fjord deglaciation below ∼500 m asl between 10.0 and 8.5 ka. Both increasing air and ocean temperatures were pivotal in driving surface lowering and submarine melt during deglaciation, but the final withdrawal of ice through Nioghalvfjerdsfjorden was facilitated by the action of marine ice sheet instability. Our estimates show that thinning and retreat rates reached a maximum of 5.29 ma −1 and 613 ma −1 , respectively, as the ice margin withdrew westwards. This would place the Early Holocene disintegration of this outlet of the NEGIS at the upper bounds of contemporary thinning and retreat rates seen both in Greenland and Antarctica. Combined with recent evidence of ... |
format |
Article in Journal/Newspaper |
author |
Roberts, David Lane, Timothy Jones, Richard Bentley, Michael Darvill, Christopher Rodes, Angel Smith, James Jamieson, Stewart Rea, Brice Fabel , Derek Gheorghiu, Delia M. Davidson, Allan Cofaigh, Colm Ó Lloyd, Jerry m. Callard, S. louise Humbert, Angelika |
author_facet |
Roberts, David Lane, Timothy Jones, Richard Bentley, Michael Darvill, Christopher Rodes, Angel Smith, James Jamieson, Stewart Rea, Brice Fabel , Derek Gheorghiu, Delia M. Davidson, Allan Cofaigh, Colm Ó Lloyd, Jerry m. Callard, S. louise Humbert, Angelika |
author_sort |
Roberts, David |
title |
The deglacial history of 79N glacier and the Northeast Greenland Ice Stream |
title_short |
The deglacial history of 79N glacier and the Northeast Greenland Ice Stream |
title_full |
The deglacial history of 79N glacier and the Northeast Greenland Ice Stream |
title_fullStr |
The deglacial history of 79N glacier and the Northeast Greenland Ice Stream |
title_full_unstemmed |
The deglacial history of 79N glacier and the Northeast Greenland Ice Stream |
title_sort |
deglacial history of 79n glacier and the northeast greenland ice stream |
publishDate |
2024 |
url |
https://research.manchester.ac.uk/en/publications/75d83eff-0528-4640-a8e5-76d4c9a22a0b https://doi.org/10.1016/j.quascirev.2024.108770 |
genre |
Antarc* Antarctica glacier Greenland Ice Sheet Nioghalvfjerdsfjorden North Atlantic |
genre_facet |
Antarc* Antarctica glacier Greenland Ice Sheet Nioghalvfjerdsfjorden North Atlantic |
op_source |
Roberts , D , Lane , T , Jones , R , Bentley , M , Darvill , C , Rodes , A , Smith , J , Jamieson , S , Rea , B , Fabel , D , Gheorghiu , D M , Davidson , A , Cofaigh , C Ó , Lloyd , J M , Callard , S L & Humbert , A 2024 , ' The deglacial history of 79N glacier and the Northeast Greenland Ice Stream ' , Quaternary Science Reviews , vol. 336 , 108770 . https://doi.org/10.1016/j.quascirev.2024.108770 |
op_relation |
https://research.manchester.ac.uk/en/publications/75d83eff-0528-4640-a8e5-76d4c9a22a0b |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.quascirev.2024.108770 |
container_title |
Quaternary Science Reviews |
container_volume |
336 |
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108770 |
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1810489911182098432 |