Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015
The Wordie Ice ShelfFleming Glacier system in the southern Antarctic Peninsula has experienced a long-term retreat and disintegration of its ice shelf in the past 50 years. Increases in the glacier velocity and dynamic thinning have been observed over the past two decades, especially after 2008 when...
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Online Access: | https://doi.org/10.5194/tc-12-2653-2018 http://ecite.utas.edu.au/127893 |
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ftunivtasecite:oai:ecite.utas.edu.au:127893 2023-05-15T13:55:18+02:00 Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015 Zhao, C Gladstone, RM Warner, RC King, MA Zwinger, T Morlighem, M 2018 application/pdf https://doi.org/10.5194/tc-12-2653-2018 http://ecite.utas.edu.au/127893 en eng Copernicus GmbH http://ecite.utas.edu.au/127893/2/127893 - Basal friction of Fleming Glacier Antarctica Part 2.pdf http://dx.doi.org/10.5194/tc-12-2653-2018 Zhao, C and Gladstone, RM and Warner, RC and King, MA and Zwinger, T and Morlighem, M, Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015, The Cryosphere, 12, (8) pp. 2653-2666. ISSN 1994-0416 (2018) [Refereed Article] http://ecite.utas.edu.au/127893 Earth Sciences Physical Geography and Environmental Geoscience Glaciology Refereed Article PeerReviewed 2018 ftunivtasecite https://doi.org/10.5194/tc-12-2653-2018 2019-12-13T22:26:07Z The Wordie Ice ShelfFleming Glacier system in the southern Antarctic Peninsula has experienced a long-term retreat and disintegration of its ice shelf in the past 50 years. Increases in the glacier velocity and dynamic thinning have been observed over the past two decades, especially after 2008 when only a small ice shelf remained at the Fleming Glacier front. It is important to know whether the substantial further speed-up and greater surface draw-down of the glacier since 2008 is a direct response to ocean forcing, or driven by feedbacks within the grounded marine-based glacier system, or both. Recent observational studies have suggested the 20082015 velocity change was due to the ungrounding of the Fleming Glacier front. To explore the mechanisms underlying the recent changes, we use a full-Stokes ice sheet model to simulate the basal shear stress distribution of the Fleming system in 2008 and 2015. This study is part of the first high resolution modelling campaign of this system. Comparison of inversions for basal shear stresses for 2008 and 2015 suggests the migration of the grounding line ∼9 km upstream by 2015 from the 2008 ice front/grounding line positions, which virtually coincided with the 1996 grounding line position. This migration is consistent with the change in floating area deduced from the calculated height above buoyancy in 2015. The retrograde submarine bed underneath the lowest part of the Fleming Glacier may have promoted retreat of the grounding line. Grounding line retreat may also be enhanced by a feedback mechanism upstream of the grounding line by which increased basal lubrication due to increasing frictional heating enhances sliding and thinning. Improved knowledge of bed topography near the grounding line and further transient simulations with oceanic forcing are required to accurately predict the future movement of the Fleming Glacier system grounding line and better understand its ice dynamics and future contribution to sea level. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Ice Sheet Ice Shelf The Cryosphere eCite UTAS (University of Tasmania) Antarctic Antarctic Peninsula Wordie ENVELOPE(-67.500,-67.500,-69.167,-69.167) Fleming Glacier ENVELOPE(-66.183,-66.183,-69.467,-69.467) The Cryosphere 12 8 2653 2666 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Physical Geography and Environmental Geoscience Glaciology |
spellingShingle |
Earth Sciences Physical Geography and Environmental Geoscience Glaciology Zhao, C Gladstone, RM Warner, RC King, MA Zwinger, T Morlighem, M Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015 |
topic_facet |
Earth Sciences Physical Geography and Environmental Geoscience Glaciology |
description |
The Wordie Ice ShelfFleming Glacier system in the southern Antarctic Peninsula has experienced a long-term retreat and disintegration of its ice shelf in the past 50 years. Increases in the glacier velocity and dynamic thinning have been observed over the past two decades, especially after 2008 when only a small ice shelf remained at the Fleming Glacier front. It is important to know whether the substantial further speed-up and greater surface draw-down of the glacier since 2008 is a direct response to ocean forcing, or driven by feedbacks within the grounded marine-based glacier system, or both. Recent observational studies have suggested the 20082015 velocity change was due to the ungrounding of the Fleming Glacier front. To explore the mechanisms underlying the recent changes, we use a full-Stokes ice sheet model to simulate the basal shear stress distribution of the Fleming system in 2008 and 2015. This study is part of the first high resolution modelling campaign of this system. Comparison of inversions for basal shear stresses for 2008 and 2015 suggests the migration of the grounding line ∼9 km upstream by 2015 from the 2008 ice front/grounding line positions, which virtually coincided with the 1996 grounding line position. This migration is consistent with the change in floating area deduced from the calculated height above buoyancy in 2015. The retrograde submarine bed underneath the lowest part of the Fleming Glacier may have promoted retreat of the grounding line. Grounding line retreat may also be enhanced by a feedback mechanism upstream of the grounding line by which increased basal lubrication due to increasing frictional heating enhances sliding and thinning. Improved knowledge of bed topography near the grounding line and further transient simulations with oceanic forcing are required to accurately predict the future movement of the Fleming Glacier system grounding line and better understand its ice dynamics and future contribution to sea level. |
format |
Article in Journal/Newspaper |
author |
Zhao, C Gladstone, RM Warner, RC King, MA Zwinger, T Morlighem, M |
author_facet |
Zhao, C Gladstone, RM Warner, RC King, MA Zwinger, T Morlighem, M |
author_sort |
Zhao, C |
title |
Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015 |
title_short |
Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015 |
title_full |
Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015 |
title_fullStr |
Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015 |
title_full_unstemmed |
Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015 |
title_sort |
basal friction of fleming glacier, antarctica - part 2: evolution from 2008 to 2015 |
publisher |
Copernicus GmbH |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-12-2653-2018 http://ecite.utas.edu.au/127893 |
long_lat |
ENVELOPE(-67.500,-67.500,-69.167,-69.167) ENVELOPE(-66.183,-66.183,-69.467,-69.467) |
geographic |
Antarctic Antarctic Peninsula Wordie Fleming Glacier |
geographic_facet |
Antarctic Antarctic Peninsula Wordie Fleming Glacier |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Ice Sheet Ice Shelf The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Ice Sheet Ice Shelf The Cryosphere |
op_relation |
http://ecite.utas.edu.au/127893/2/127893 - Basal friction of Fleming Glacier Antarctica Part 2.pdf http://dx.doi.org/10.5194/tc-12-2653-2018 Zhao, C and Gladstone, RM and Warner, RC and King, MA and Zwinger, T and Morlighem, M, Basal friction of Fleming Glacier, Antarctica - Part 2: evolution from 2008 to 2015, The Cryosphere, 12, (8) pp. 2653-2666. ISSN 1994-0416 (2018) [Refereed Article] http://ecite.utas.edu.au/127893 |
op_doi |
https://doi.org/10.5194/tc-12-2653-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
8 |
container_start_page |
2653 |
op_container_end_page |
2666 |
_version_ |
1766261680981934080 |