Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling
We present a diagnostic glacier flowline model parameterized and constrained by new velocity data from ice-surface GPS installations and speckle tracking of TerraSAR-X satellite images, newly acquired airborne-radar data, and continental gridded datasets of topography and geothermal heat flux, in or...
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University of Canterbury. Gateway Antarctica
2014
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Online Access: | http://hdl.handle.net/10092/11690 https://doi.org/10.3189/2014JoG13J131 |
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ftunivcanter:oai:ir.canterbury.ac.nz:10092/11690 2023-05-15T13:55:49+02:00 Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling Golledge, N.R. Marsh, O.J. Rack, W. Braaten, D. Jones, R.S. 2014 application/pdf http://hdl.handle.net/10092/11690 https://doi.org/10.3189/2014JoG13J131 en eng University of Canterbury. Gateway Antarctica Golledge, N.R., Marsh, O.J., Rack, W., Braaten, D., Jones, R.S. (2014) Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling. Journal of Glaciology, 60(223), pp. 855-866. http://hdl.handle.net/10092/11690 https://doi.org/10.3189/2014JoG13J131 https://hdl.handle.net/10092/17651 Antarctic glaciology glacier flow glacier modelling ice dynamics ice-sheet modelling Fields of Research::37 - Earth sciences::3709 - Physical geography and environmental geoscience::370902 - Glaciology Journal Article 2014 ftunivcanter https://doi.org/10.3189/2014JoG13J131 2022-09-08T13:31:29Z We present a diagnostic glacier flowline model parameterized and constrained by new velocity data from ice-surface GPS installations and speckle tracking of TerraSAR-X satellite images, newly acquired airborne-radar data, and continental gridded datasets of topography and geothermal heat flux, in order to better understand two outlet glaciers of the East Antarctic ice sheet. Our observational data are employed as primary inputs to a modelling procedure that first calculates the basal thermal regime of each glacier, then iterates the basal sliding coefficient and deformation rate parameter until the fit of simulated to observed surface velocities is optimized. We find that the two glaciers have both frozen and thawed areas at their beds, facilitating partial sliding. Glacier flow arises from a balance between sliding and deformation that fluctuates along the length of each glacier, with the amount of sliding typically varying by up to two orders of magnitude but with deformation rates far more constant. Beardmore Glacier is warmer and faster-flowing than Skelton Glacier, but an up-glacier deepening bed at the grounding line, coupled with ice thicknesses close to flotation, lead us to infer a greater vulnerability of Skelton Glacier to grounding-line recession if affected by ocean-forced thinning and concomitant acceleration. Article in Journal/Newspaper Antarc* Antarctic Beardmore Glacier Ice Sheet Journal of Glaciology Skelton Glacier University of Canterbury, Christchurch: UC Research Repository Antarctic Beardmore ENVELOPE(174.900,174.900,-83.350,-83.350) Beardmore Glacier ENVELOPE(170.000,170.000,-84.500,-84.500) East Antarctic Ice Sheet Skelton Glacier ENVELOPE(161.500,161.500,-78.583,-78.583) Transantarctic Mountains Journal of Glaciology 60 223 855 866 |
institution |
Open Polar |
collection |
University of Canterbury, Christchurch: UC Research Repository |
op_collection_id |
ftunivcanter |
language |
English |
topic |
Antarctic glaciology glacier flow glacier modelling ice dynamics ice-sheet modelling Fields of Research::37 - Earth sciences::3709 - Physical geography and environmental geoscience::370902 - Glaciology |
spellingShingle |
Antarctic glaciology glacier flow glacier modelling ice dynamics ice-sheet modelling Fields of Research::37 - Earth sciences::3709 - Physical geography and environmental geoscience::370902 - Glaciology Golledge, N.R. Marsh, O.J. Rack, W. Braaten, D. Jones, R.S. Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling |
topic_facet |
Antarctic glaciology glacier flow glacier modelling ice dynamics ice-sheet modelling Fields of Research::37 - Earth sciences::3709 - Physical geography and environmental geoscience::370902 - Glaciology |
description |
We present a diagnostic glacier flowline model parameterized and constrained by new velocity data from ice-surface GPS installations and speckle tracking of TerraSAR-X satellite images, newly acquired airborne-radar data, and continental gridded datasets of topography and geothermal heat flux, in order to better understand two outlet glaciers of the East Antarctic ice sheet. Our observational data are employed as primary inputs to a modelling procedure that first calculates the basal thermal regime of each glacier, then iterates the basal sliding coefficient and deformation rate parameter until the fit of simulated to observed surface velocities is optimized. We find that the two glaciers have both frozen and thawed areas at their beds, facilitating partial sliding. Glacier flow arises from a balance between sliding and deformation that fluctuates along the length of each glacier, with the amount of sliding typically varying by up to two orders of magnitude but with deformation rates far more constant. Beardmore Glacier is warmer and faster-flowing than Skelton Glacier, but an up-glacier deepening bed at the grounding line, coupled with ice thicknesses close to flotation, lead us to infer a greater vulnerability of Skelton Glacier to grounding-line recession if affected by ocean-forced thinning and concomitant acceleration. |
format |
Article in Journal/Newspaper |
author |
Golledge, N.R. Marsh, O.J. Rack, W. Braaten, D. Jones, R.S. |
author_facet |
Golledge, N.R. Marsh, O.J. Rack, W. Braaten, D. Jones, R.S. |
author_sort |
Golledge, N.R. |
title |
Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling |
title_short |
Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling |
title_full |
Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling |
title_fullStr |
Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling |
title_full_unstemmed |
Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling |
title_sort |
basal conditions of two transantarctic mountains outlet glaciers from observation-constrained diagnostic modelling |
publisher |
University of Canterbury. Gateway Antarctica |
publishDate |
2014 |
url |
http://hdl.handle.net/10092/11690 https://doi.org/10.3189/2014JoG13J131 |
long_lat |
ENVELOPE(174.900,174.900,-83.350,-83.350) ENVELOPE(170.000,170.000,-84.500,-84.500) ENVELOPE(161.500,161.500,-78.583,-78.583) |
geographic |
Antarctic Beardmore Beardmore Glacier East Antarctic Ice Sheet Skelton Glacier Transantarctic Mountains |
geographic_facet |
Antarctic Beardmore Beardmore Glacier East Antarctic Ice Sheet Skelton Glacier Transantarctic Mountains |
genre |
Antarc* Antarctic Beardmore Glacier Ice Sheet Journal of Glaciology Skelton Glacier |
genre_facet |
Antarc* Antarctic Beardmore Glacier Ice Sheet Journal of Glaciology Skelton Glacier |
op_relation |
Golledge, N.R., Marsh, O.J., Rack, W., Braaten, D., Jones, R.S. (2014) Basal conditions of two Transantarctic Mountains outlet glaciers from observation-constrained diagnostic modelling. Journal of Glaciology, 60(223), pp. 855-866. http://hdl.handle.net/10092/11690 https://doi.org/10.3189/2014JoG13J131 |
op_rights |
https://hdl.handle.net/10092/17651 |
op_doi |
https://doi.org/10.3189/2014JoG13J131 |
container_title |
Journal of Glaciology |
container_volume |
60 |
container_issue |
223 |
container_start_page |
855 |
op_container_end_page |
866 |
_version_ |
1766262695334510592 |