Basal friction of Fleming Glacier, Antarctica - Part 2: Evolution from 2008 to 2015
The Wordie Ice Shelf-Fleming 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 whe...
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ftcdlib:oai:escholarship.org/ark:/13030/qt8164710w 2023-05-15T14:04:02+02:00 Basal friction of Fleming Glacier, Antarctica - Part 2: Evolution from 2008 to 2015 Zhao, C Gladstone, RMM Warner, RC King, MA Zwinger, T Morlighem, M 2653 - 2666 2018-08-15 https://escholarship.org/uc/item/8164710w unknown eScholarship, University of California qt8164710w https://escholarship.org/uc/item/8164710w public Cryosphere, vol 12, iss 8 Meteorology & Atmospheric Sciences Oceanography Physical Geography and Environmental Geoscience article 2018 ftcdlib 2021-04-16T07:11:37Z The Wordie Ice Shelf-Fleming 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 2008-2015 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 ĝ1/4 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 Wordie Ice Shelf University of California: eScholarship Antarctic Antarctic Peninsula Fleming Glacier ENVELOPE(-66.183,-66.183,-69.467,-69.467) Wordie ENVELOPE(-67.500,-67.500,-69.167,-69.167) Wordie Ice Shelf ENVELOPE(-67.750,-67.750,-69.250,-69.250) |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Meteorology & Atmospheric Sciences Oceanography Physical Geography and Environmental Geoscience |
spellingShingle |
Meteorology & Atmospheric Sciences Oceanography Physical Geography and Environmental Geoscience Zhao, C Gladstone, RMM Warner, RC King, MA Zwinger, T Morlighem, M Basal friction of Fleming Glacier, Antarctica - Part 2: Evolution from 2008 to 2015 |
topic_facet |
Meteorology & Atmospheric Sciences Oceanography Physical Geography and Environmental Geoscience |
description |
The Wordie Ice Shelf-Fleming 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 2008-2015 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 ĝ1/4 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, RMM Warner, RC King, MA Zwinger, T Morlighem, M |
author_facet |
Zhao, C Gladstone, RMM 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 |
eScholarship, University of California |
publishDate |
2018 |
url |
https://escholarship.org/uc/item/8164710w |
op_coverage |
2653 - 2666 |
long_lat |
ENVELOPE(-66.183,-66.183,-69.467,-69.467) ENVELOPE(-67.500,-67.500,-69.167,-69.167) ENVELOPE(-67.750,-67.750,-69.250,-69.250) |
geographic |
Antarctic Antarctic Peninsula Fleming Glacier Wordie Wordie Ice Shelf |
geographic_facet |
Antarctic Antarctic Peninsula Fleming Glacier Wordie Wordie Ice Shelf |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Ice Sheet Ice Shelf Wordie Ice Shelf |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Ice Sheet Ice Shelf Wordie Ice Shelf |
op_source |
Cryosphere, vol 12, iss 8 |
op_relation |
qt8164710w https://escholarship.org/uc/item/8164710w |
op_rights |
public |
_version_ |
1766274971324121088 |