Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years
The discovery of Antarctica's deepest subglacial trough beneath the Denman Glacier, combined with high rates of basal melt at the grounding line, has caused significant concern over its vulnerability to retreat. Recent attention has therefore been focusing on understanding the controls driving...
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Online Access: | https://doi.org/10.5194/tc-17-157-2023 http://ecite.utas.edu.au/155537 |
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ftunivtasecite:oai:ecite.utas.edu.au:155537 2023-06-11T04:05:06+02:00 Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years Thompson, SS Kulessa, B Luckman, A Halpin, JA Greenbaum, JS Pelle, T Habbal, F Guo, J Jong, LM Roberts, JL Sun, B Blankenship, DD 2023 application/pdf https://doi.org/10.5194/tc-17-157-2023 http://ecite.utas.edu.au/155537 en eng Copernicus GmbH http://ecite.utas.edu.au/155537/1/155537 - Glaciological history and structural evolution of the Shackleton Ice Shelf system.pdf http://dx.doi.org/10.5194/tc-17-157-2023 Thompson, SS and Kulessa, B and Luckman, A and Halpin, JA and Greenbaum, JS and Pelle, T and Habbal, F and Guo, J and Jong, LM and Roberts, JL and Sun, B and Blankenship, DD, Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years, Cryosphere, 17, (1) pp. 157-174. ISSN 1994-0416 (2023) [Refereed Article] http://ecite.utas.edu.au/155537 Earth Sciences Physical geography and environmental geoscience Glaciology Refereed Article PeerReviewed 2023 ftunivtasecite https://doi.org/10.5194/tc-17-157-2023 2023-04-24T22:17:53Z The discovery of Antarctica's deepest subglacial trough beneath the Denman Glacier, combined with high rates of basal melt at the grounding line, has caused significant concern over its vulnerability to retreat. Recent attention has therefore been focusing on understanding the controls driving Denman Glacier's dynamic evolution. Here we consider the Shackleton system, comprised of the Shackleton Ice Shelf, Denman Glacier, and the adjacent Scott, Northcliff, Roscoe and Apfel glaciers, about which almost nothing is known. We widen the context of previously observed dynamic changes in the Denman Glacier to the wider region of the Shackleton system, with a multi-decadal time frame and an improved biannual temporal frequency of observations in the last 7 years (2015-2022). We integrate new satellite observations of ice structure and airborne radar data with changes in ice front position and ice flow velocities to investigate changes in the system. Over the 60-year period of observation we find significant rift propagation on the Shackleton Ice Shelf and Scott Glacier and notable structural changes in the floating shear margins between the ice shelf and the outlet glaciers, as well as features indicative of ice with elevated salt concentration and brine infiltration in regions of the system. Over the period 2017-2022 we observe a significant increase in ice flow speed (up to 50 %) on the floating part of Scott Glacier, coincident with small-scale calving and rift propagation close to the ice front. We do not observe any seasonal variation or significant change in ice flow speed across the rest of the Shackleton system. Given the potential vulnerability of the system to accelerating retreat into the overdeepened, potentially sediment-filled bedrock trough, an improved understanding of the glaciological, oceanographic and geological conditions in the Shackleton system are required to improve the certainty of numerical model predictions, and we identify a number of priorities for future research. With access to these ... Article in Journal/Newspaper Antarc* Antarctica Denman Glacier East Antarctica Ice Shelf Scott Glacier Shackleton Ice Shelf eCite UTAS (University of Tasmania) East Antarctica Shackleton Shackleton Ice Shelf ENVELOPE(100.504,100.504,-65.996,-65.996) Denman Glacier ENVELOPE(99.417,99.417,-66.750,-66.750) The Cryosphere 17 1 157 174 |
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 Thompson, SS Kulessa, B Luckman, A Halpin, JA Greenbaum, JS Pelle, T Habbal, F Guo, J Jong, LM Roberts, JL Sun, B Blankenship, DD Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years |
topic_facet |
Earth Sciences Physical geography and environmental geoscience Glaciology |
description |
The discovery of Antarctica's deepest subglacial trough beneath the Denman Glacier, combined with high rates of basal melt at the grounding line, has caused significant concern over its vulnerability to retreat. Recent attention has therefore been focusing on understanding the controls driving Denman Glacier's dynamic evolution. Here we consider the Shackleton system, comprised of the Shackleton Ice Shelf, Denman Glacier, and the adjacent Scott, Northcliff, Roscoe and Apfel glaciers, about which almost nothing is known. We widen the context of previously observed dynamic changes in the Denman Glacier to the wider region of the Shackleton system, with a multi-decadal time frame and an improved biannual temporal frequency of observations in the last 7 years (2015-2022). We integrate new satellite observations of ice structure and airborne radar data with changes in ice front position and ice flow velocities to investigate changes in the system. Over the 60-year period of observation we find significant rift propagation on the Shackleton Ice Shelf and Scott Glacier and notable structural changes in the floating shear margins between the ice shelf and the outlet glaciers, as well as features indicative of ice with elevated salt concentration and brine infiltration in regions of the system. Over the period 2017-2022 we observe a significant increase in ice flow speed (up to 50 %) on the floating part of Scott Glacier, coincident with small-scale calving and rift propagation close to the ice front. We do not observe any seasonal variation or significant change in ice flow speed across the rest of the Shackleton system. Given the potential vulnerability of the system to accelerating retreat into the overdeepened, potentially sediment-filled bedrock trough, an improved understanding of the glaciological, oceanographic and geological conditions in the Shackleton system are required to improve the certainty of numerical model predictions, and we identify a number of priorities for future research. With access to these ... |
format |
Article in Journal/Newspaper |
author |
Thompson, SS Kulessa, B Luckman, A Halpin, JA Greenbaum, JS Pelle, T Habbal, F Guo, J Jong, LM Roberts, JL Sun, B Blankenship, DD |
author_facet |
Thompson, SS Kulessa, B Luckman, A Halpin, JA Greenbaum, JS Pelle, T Habbal, F Guo, J Jong, LM Roberts, JL Sun, B Blankenship, DD |
author_sort |
Thompson, SS |
title |
Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years |
title_short |
Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years |
title_full |
Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years |
title_fullStr |
Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years |
title_full_unstemmed |
Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years |
title_sort |
glaciological history and structural evolution of the shackleton ice shelf system, east antarctica, over the past 60 years |
publisher |
Copernicus GmbH |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-157-2023 http://ecite.utas.edu.au/155537 |
long_lat |
ENVELOPE(100.504,100.504,-65.996,-65.996) ENVELOPE(99.417,99.417,-66.750,-66.750) |
geographic |
East Antarctica Shackleton Shackleton Ice Shelf Denman Glacier |
geographic_facet |
East Antarctica Shackleton Shackleton Ice Shelf Denman Glacier |
genre |
Antarc* Antarctica Denman Glacier East Antarctica Ice Shelf Scott Glacier Shackleton Ice Shelf |
genre_facet |
Antarc* Antarctica Denman Glacier East Antarctica Ice Shelf Scott Glacier Shackleton Ice Shelf |
op_relation |
http://ecite.utas.edu.au/155537/1/155537 - Glaciological history and structural evolution of the Shackleton Ice Shelf system.pdf http://dx.doi.org/10.5194/tc-17-157-2023 Thompson, SS and Kulessa, B and Luckman, A and Halpin, JA and Greenbaum, JS and Pelle, T and Habbal, F and Guo, J and Jong, LM and Roberts, JL and Sun, B and Blankenship, DD, Glaciological history and structural evolution of the Shackleton Ice Shelf system, East Antarctica, over the past 60 years, Cryosphere, 17, (1) pp. 157-174. ISSN 1994-0416 (2023) [Refereed Article] http://ecite.utas.edu.au/155537 |
op_doi |
https://doi.org/10.5194/tc-17-157-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
1 |
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157 |
op_container_end_page |
174 |
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1768371852431851520 |