The control of an uncharted pinning point on the flow of an Antarctic ice shelf
Abstract: Antarctic ice shelves are buttressed by numerous pinning points attaching to the otherwise freely-floating ice from below. Some of these kilometric-scale grounded features are unresolved in Antarctic-wide datasets of ice thickness and bathymetry, hampering ice flow models to fully capture...
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Language: | English |
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Online Access: | https://hdl.handle.net/10067/1342310151162165141 https://repository.uantwerpen.be/docman/irua/afac8a/134231.pdf |
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ftunivantwerpen:c:irua:134231 2023-07-16T03:53:38+02:00 The control of an uncharted pinning point on the flow of an Antarctic ice shelf Berger, Sophie Favier, Lionel Drews, Reinhard Derwael, Jean-Jacques Pattyn, Frank 2016 pdf https://hdl.handle.net/10067/1342310151162165141 https://repository.uantwerpen.be/docman/irua/afac8a/134231.pdf eng eng info:eu-repo/semantics/altIdentifier/doi/10.1017/JOG.2016.7 info:eu-repo/semantics/altIdentifier/isi/000376838400004 info:eu-repo/semantics/openAccess 0022-1430 Journal of glaciology Economics Physics info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2016 ftunivantwerpen https://doi.org/10.1017/JOG.2016.7 2023-06-26T22:20:33Z Abstract: Antarctic ice shelves are buttressed by numerous pinning points attaching to the otherwise freely-floating ice from below. Some of these kilometric-scale grounded features are unresolved in Antarctic-wide datasets of ice thickness and bathymetry, hampering ice flow models to fully capture dynamics at the grounding line and upstream. We investigate the role of an 8.7 km(2) pinning point at the front of the Roi Baudouin Ice Shelf, East Antarctica. Using ERS interferometry and ALOS-PALSAR speckle tracking, we derive, on a 125 m grid spacing, surface velocities deviating by -5.2 +/- 4.5 m a(-1) from 37 on-site global navigation satellite systems-derived velocities. We find no evidence for ice flow changes on decadal time scales and we show that ice on the pinning point virtually stagnates, deviating the ice stream and causing enhanced horizontal shearing upstream. Using the BISICLES ice-flow model, we invert for basal friction and ice rigidity with three input scenarios of ice velocity and geometry. We show that inversion results are the most sensitive to the presence/absence of the pinning point in the bathymetry; surface velocities at the pinning point are of secondary importance. Undersampling of pinning points results in erroneous ice-shelf properties in models initialised by control methods. This may impact prognostic modelling for ice-sheet evolution in the case of unpinning. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ice Shelves Journal of Glaciology IRUA - Institutional Repository van de Universiteit Antwerpen Antarctic East Antarctica Roi Baudouin ENVELOPE(24.461,24.461,-70.438,-70.438) Journal of Glaciology 62 231 37 45 |
institution |
Open Polar |
collection |
IRUA - Institutional Repository van de Universiteit Antwerpen |
op_collection_id |
ftunivantwerpen |
language |
English |
topic |
Economics Physics |
spellingShingle |
Economics Physics Berger, Sophie Favier, Lionel Drews, Reinhard Derwael, Jean-Jacques Pattyn, Frank The control of an uncharted pinning point on the flow of an Antarctic ice shelf |
topic_facet |
Economics Physics |
description |
Abstract: Antarctic ice shelves are buttressed by numerous pinning points attaching to the otherwise freely-floating ice from below. Some of these kilometric-scale grounded features are unresolved in Antarctic-wide datasets of ice thickness and bathymetry, hampering ice flow models to fully capture dynamics at the grounding line and upstream. We investigate the role of an 8.7 km(2) pinning point at the front of the Roi Baudouin Ice Shelf, East Antarctica. Using ERS interferometry and ALOS-PALSAR speckle tracking, we derive, on a 125 m grid spacing, surface velocities deviating by -5.2 +/- 4.5 m a(-1) from 37 on-site global navigation satellite systems-derived velocities. We find no evidence for ice flow changes on decadal time scales and we show that ice on the pinning point virtually stagnates, deviating the ice stream and causing enhanced horizontal shearing upstream. Using the BISICLES ice-flow model, we invert for basal friction and ice rigidity with three input scenarios of ice velocity and geometry. We show that inversion results are the most sensitive to the presence/absence of the pinning point in the bathymetry; surface velocities at the pinning point are of secondary importance. Undersampling of pinning points results in erroneous ice-shelf properties in models initialised by control methods. This may impact prognostic modelling for ice-sheet evolution in the case of unpinning. |
format |
Article in Journal/Newspaper |
author |
Berger, Sophie Favier, Lionel Drews, Reinhard Derwael, Jean-Jacques Pattyn, Frank |
author_facet |
Berger, Sophie Favier, Lionel Drews, Reinhard Derwael, Jean-Jacques Pattyn, Frank |
author_sort |
Berger, Sophie |
title |
The control of an uncharted pinning point on the flow of an Antarctic ice shelf |
title_short |
The control of an uncharted pinning point on the flow of an Antarctic ice shelf |
title_full |
The control of an uncharted pinning point on the flow of an Antarctic ice shelf |
title_fullStr |
The control of an uncharted pinning point on the flow of an Antarctic ice shelf |
title_full_unstemmed |
The control of an uncharted pinning point on the flow of an Antarctic ice shelf |
title_sort |
control of an uncharted pinning point on the flow of an antarctic ice shelf |
publishDate |
2016 |
url |
https://hdl.handle.net/10067/1342310151162165141 https://repository.uantwerpen.be/docman/irua/afac8a/134231.pdf |
long_lat |
ENVELOPE(24.461,24.461,-70.438,-70.438) |
geographic |
Antarctic East Antarctica Roi Baudouin |
geographic_facet |
Antarctic East Antarctica Roi Baudouin |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ice Shelves Journal of Glaciology |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelf Ice Shelves Journal of Glaciology |
op_source |
0022-1430 Journal of glaciology |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1017/JOG.2016.7 info:eu-repo/semantics/altIdentifier/isi/000376838400004 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1017/JOG.2016.7 |
container_title |
Journal of Glaciology |
container_volume |
62 |
container_issue |
231 |
container_start_page |
37 |
op_container_end_page |
45 |
_version_ |
1771551107660644352 |