The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland
The northern sector of the Greenland Ice Sheet is considered to be particularly susceptible to ice mass loss arising from increased glacier discharge in the coming decades. However, the past extent and dynamics of outlet glaciers in this region, and hence their vulnerability to climate change, are p...
Published in: | The Cryosphere |
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Main Authors: | , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2021
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Online Access: | https://pure.au.dk/portal/da/publications/the-holocene-dynamics-of-ryder-glacier-and-ice-tongue-in-north-greenland(9d446b6f-7a8c-48a4-ad32-17d2a2edf685).html https://doi.org/10.5194/tc-15-4073-2021 http://www.scopus.com/inward/record.url?scp=85113912583&partnerID=8YFLogxK |
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Aarhus University: Research |
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language |
English |
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The northern sector of the Greenland Ice Sheet is considered to be particularly susceptible to ice mass loss arising from increased glacier discharge in the coming decades. However, the past extent and dynamics of outlet glaciers in this region, and hence their vulnerability to climate change, are poorly documented. In the summer of 2019, the Swedish icebreaker Oden entered the previously unchartered waters of Sherard Osborn Fjord, where Ryder Glacier drains approximately 2 % of Greenland's ice sheet into the Lincoln Sea. Here we reconstruct the Holocene dynamics of Ryder Glacier and its ice tongue by combining radiocarbon dating with sedimentary facies analyses along a 45 km transect of marine sediment cores collected between the modern ice tongue margin and the mouth of the fjord. The results illustrate that Ryder Glacier retreated from a grounded position at the fjord mouth during the Early Holocene (> 10:7 ± 0:4 ka cal BP) and receded more than 120 km to the end of Sherard Osborn Fjord by the Middle Holocene (6:3 ± 0:3 ka cal BP), likely becoming completely land-based. A re-advance of Ryder Glacier occurred in the Late Holocene, becoming marinebased around 3:9 ± 0:4 ka cal BP. An ice tongue, similar in extent to its current position was established in the Late Holocene (between 3:6 ± 0:4 and 2:9 ± 0:4 ka cal BP) and extended to its maximum historical position near the fjord mouth around 0:9±0:3 ka cal BP. Laminated, clast-poor sediments were deposited during the entire retreat and regrowth phases, suggesting the persistence of an ice tongue that only collapsed when the glacier retreated behind a prominent topographic high at the landward end of the fjord. Sherard Osborn Fjord narrows inland, is constrained by steep-sided cliffs, contains a number of bathymetric pinning points that also shield the modern ice tongue and grounding zone from warm Atlantic waters, and has a shallowing inland sub-ice topography. These features are conducive to glacier stability and can explain the persistence of Ryder's ice tongue while the glacier remained marine-based. However, the physiography of the fjord did not halt the dramatic retreat of Ryder Glacier under the relatively mild changes in climate forcing during the Holocene. Presently, Ryder Glacier is grounded more than 40 km seaward of its inferred position during the Middle Holocene, highlighting the potential for substantial retreat in response to ongoing climate change. |
format |
Article in Journal/Newspaper |
author |
O'Regan, Matt Cronin, Thomas M. Reilly, Brendan Alstrup, Aage Kristian Olsen Gemery, Laura Golub, Anna Mayer, Larry A. Morlighem, Mathieu Moros, Matthias Munk, Ole L. Nilsson, Johan Pearce, Christof Detlef, Henrieka Stranne, Christian Vermassen, Flor West, Gabriel Jakobsson, Martin |
spellingShingle |
O'Regan, Matt Cronin, Thomas M. Reilly, Brendan Alstrup, Aage Kristian Olsen Gemery, Laura Golub, Anna Mayer, Larry A. Morlighem, Mathieu Moros, Matthias Munk, Ole L. Nilsson, Johan Pearce, Christof Detlef, Henrieka Stranne, Christian Vermassen, Flor West, Gabriel Jakobsson, Martin The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland |
author_facet |
O'Regan, Matt Cronin, Thomas M. Reilly, Brendan Alstrup, Aage Kristian Olsen Gemery, Laura Golub, Anna Mayer, Larry A. Morlighem, Mathieu Moros, Matthias Munk, Ole L. Nilsson, Johan Pearce, Christof Detlef, Henrieka Stranne, Christian Vermassen, Flor West, Gabriel Jakobsson, Martin |
author_sort |
O'Regan, Matt |
title |
The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland |
title_short |
The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland |
title_full |
The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland |
title_fullStr |
The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland |
title_full_unstemmed |
The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland |
title_sort |
holocene dynamics of ryder glacier and ice tongue in north greenland |
publishDate |
2021 |
url |
https://pure.au.dk/portal/da/publications/the-holocene-dynamics-of-ryder-glacier-and-ice-tongue-in-north-greenland(9d446b6f-7a8c-48a4-ad32-17d2a2edf685).html https://doi.org/10.5194/tc-15-4073-2021 http://www.scopus.com/inward/record.url?scp=85113912583&partnerID=8YFLogxK |
long_lat |
ENVELOPE(-120.378,-120.378,56.604,56.604) ENVELOPE(-68.333,-68.333,-67.566,-67.566) ENVELOPE(-67.250,-67.250,-71.116,-71.116) ENVELOPE(-51.833,-51.833,82.083,82.083) |
geographic |
Greenland Osborn Ryder Ryder Glacier Sherard Osborn Fjord |
geographic_facet |
Greenland Osborn Ryder Ryder Glacier Sherard Osborn Fjord |
genre |
glacier Greenland Ice Sheet Lincoln Sea North Greenland oden Sherard Osborn fjord The Cryosphere |
genre_facet |
glacier Greenland Ice Sheet Lincoln Sea North Greenland oden Sherard Osborn fjord The Cryosphere |
op_source |
O'Regan , M , Cronin , T M , Reilly , B , Alstrup , A K O , Gemery , L , Golub , A , Mayer , L A , Morlighem , M , Moros , M , Munk , O L , Nilsson , J , Pearce , C , Detlef , H , Stranne , C , Vermassen , F , West , G & Jakobsson , M 2021 , ' The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland ' , The Cryosphere , vol. 15 , no. 8 , pp. 4073-4097 . https://doi.org/10.5194/tc-15-4073-2021 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-15-4073-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
8 |
container_start_page |
4073 |
op_container_end_page |
4097 |
_version_ |
1766009138971672576 |
spelling |
ftuniaarhuspubl:oai:pure.atira.dk:publications/9d446b6f-7a8c-48a4-ad32-17d2a2edf685 2023-05-15T16:21:07+02:00 The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland O'Regan, Matt Cronin, Thomas M. Reilly, Brendan Alstrup, Aage Kristian Olsen Gemery, Laura Golub, Anna Mayer, Larry A. Morlighem, Mathieu Moros, Matthias Munk, Ole L. Nilsson, Johan Pearce, Christof Detlef, Henrieka Stranne, Christian Vermassen, Flor West, Gabriel Jakobsson, Martin 2021-08-24 https://pure.au.dk/portal/da/publications/the-holocene-dynamics-of-ryder-glacier-and-ice-tongue-in-north-greenland(9d446b6f-7a8c-48a4-ad32-17d2a2edf685).html https://doi.org/10.5194/tc-15-4073-2021 http://www.scopus.com/inward/record.url?scp=85113912583&partnerID=8YFLogxK eng eng info:eu-repo/semantics/openAccess O'Regan , M , Cronin , T M , Reilly , B , Alstrup , A K O , Gemery , L , Golub , A , Mayer , L A , Morlighem , M , Moros , M , Munk , O L , Nilsson , J , Pearce , C , Detlef , H , Stranne , C , Vermassen , F , West , G & Jakobsson , M 2021 , ' The Holocene dynamics of Ryder Glacier and ice tongue in north Greenland ' , The Cryosphere , vol. 15 , no. 8 , pp. 4073-4097 . https://doi.org/10.5194/tc-15-4073-2021 article 2021 ftuniaarhuspubl https://doi.org/10.5194/tc-15-4073-2021 2021-12-08T23:47:25Z The northern sector of the Greenland Ice Sheet is considered to be particularly susceptible to ice mass loss arising from increased glacier discharge in the coming decades. However, the past extent and dynamics of outlet glaciers in this region, and hence their vulnerability to climate change, are poorly documented. In the summer of 2019, the Swedish icebreaker Oden entered the previously unchartered waters of Sherard Osborn Fjord, where Ryder Glacier drains approximately 2 % of Greenland's ice sheet into the Lincoln Sea. Here we reconstruct the Holocene dynamics of Ryder Glacier and its ice tongue by combining radiocarbon dating with sedimentary facies analyses along a 45 km transect of marine sediment cores collected between the modern ice tongue margin and the mouth of the fjord. The results illustrate that Ryder Glacier retreated from a grounded position at the fjord mouth during the Early Holocene (> 10:7 ± 0:4 ka cal BP) and receded more than 120 km to the end of Sherard Osborn Fjord by the Middle Holocene (6:3 ± 0:3 ka cal BP), likely becoming completely land-based. A re-advance of Ryder Glacier occurred in the Late Holocene, becoming marinebased around 3:9 ± 0:4 ka cal BP. An ice tongue, similar in extent to its current position was established in the Late Holocene (between 3:6 ± 0:4 and 2:9 ± 0:4 ka cal BP) and extended to its maximum historical position near the fjord mouth around 0:9±0:3 ka cal BP. Laminated, clast-poor sediments were deposited during the entire retreat and regrowth phases, suggesting the persistence of an ice tongue that only collapsed when the glacier retreated behind a prominent topographic high at the landward end of the fjord. Sherard Osborn Fjord narrows inland, is constrained by steep-sided cliffs, contains a number of bathymetric pinning points that also shield the modern ice tongue and grounding zone from warm Atlantic waters, and has a shallowing inland sub-ice topography. These features are conducive to glacier stability and can explain the persistence of Ryder's ice tongue while the glacier remained marine-based. However, the physiography of the fjord did not halt the dramatic retreat of Ryder Glacier under the relatively mild changes in climate forcing during the Holocene. Presently, Ryder Glacier is grounded more than 40 km seaward of its inferred position during the Middle Holocene, highlighting the potential for substantial retreat in response to ongoing climate change. Article in Journal/Newspaper glacier Greenland Ice Sheet Lincoln Sea North Greenland oden Sherard Osborn fjord The Cryosphere Aarhus University: Research Greenland Osborn ENVELOPE(-120.378,-120.378,56.604,56.604) Ryder ENVELOPE(-68.333,-68.333,-67.566,-67.566) Ryder Glacier ENVELOPE(-67.250,-67.250,-71.116,-71.116) Sherard Osborn Fjord ENVELOPE(-51.833,-51.833,82.083,82.083) The Cryosphere 15 8 4073 4097 |