A force-balance study of ice flow and basal conditions of Jutulstraumen, Antarctica
Abstract Stresses and velocities at depth are calculated across Jutulstraumen, an ice stream in Dronning Maud Land, draining about 1% of the Antarctic ice sheet. The force-balance study is based on data from kinematic GPS measurements on three strain nets, each consisting of 3 × 3 stakes. The maximu...
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Cambridge University Press (CUP)
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Online Access: | http://dx.doi.org/10.1017/s0022143000003403 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000003403 |
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crcambridgeupr:10.1017/s0022143000003403 2024-03-03T08:37:49+00:00 A force-balance study of ice flow and basal conditions of Jutulstraumen, Antarctica Armand Høydal, Øyvind 1996 http://dx.doi.org/10.1017/s0022143000003403 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000003403 en eng Cambridge University Press (CUP) Journal of Glaciology volume 42, issue 142, page 413-425 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1996 crcambridgeupr https://doi.org/10.1017/s0022143000003403 2024-02-08T08:34:04Z Abstract Stresses and velocities at depth are calculated across Jutulstraumen, an ice stream in Dronning Maud Land, draining about 1% of the Antarctic ice sheet. The force-balance study is based on data from kinematic GPS measurements on three strain nets, each consisting of 3 × 3 stakes. The maximum measured velocity is 443 m a −1 and the velocity variation over short distances is large compared with studied ice streams in West Antarctica. The surface topography together with the measured velocities across the profile indicate that the bottom topography has a great influence on the flow direction, even where the ice thickness is more than 2000 m. The basal shear stresses are calculated as 180, 227 and 146 kPa in the three Strain nets, while the corresponding driving stresses are 180, 122 and 111 kPa (±5%). The heat produced by sliding and internal deformation is sufficient to keep the base at the pressure-melting point. The annual basal melting is estimated to be about 60 mm. Investigations on the effect of temperature softening show that the flow parameter’s influence on the effective strain rate is more important than the flow parameter’s direct softening in the flow low alone. The mass flow calculated by the force-balance method is between 87 and 96% of pure plug flow and total discharge is calculated to be 13.3 ± 10 km 3 a -1 . Article in Journal/Newspaper Antarc* Antarctic Antarctica Dronning Maud Land Ice Sheet Journal of Glaciology West Antarctica Cambridge University Press Antarctic The Antarctic Dronning Maud Land West Antarctica Jutulstraumen ENVELOPE(-1.000,-1.000,-72.000,-72.000) Journal of Glaciology 42 142 413 425 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Armand Høydal, Øyvind A force-balance study of ice flow and basal conditions of Jutulstraumen, Antarctica |
topic_facet |
Earth-Surface Processes |
description |
Abstract Stresses and velocities at depth are calculated across Jutulstraumen, an ice stream in Dronning Maud Land, draining about 1% of the Antarctic ice sheet. The force-balance study is based on data from kinematic GPS measurements on three strain nets, each consisting of 3 × 3 stakes. The maximum measured velocity is 443 m a −1 and the velocity variation over short distances is large compared with studied ice streams in West Antarctica. The surface topography together with the measured velocities across the profile indicate that the bottom topography has a great influence on the flow direction, even where the ice thickness is more than 2000 m. The basal shear stresses are calculated as 180, 227 and 146 kPa in the three Strain nets, while the corresponding driving stresses are 180, 122 and 111 kPa (±5%). The heat produced by sliding and internal deformation is sufficient to keep the base at the pressure-melting point. The annual basal melting is estimated to be about 60 mm. Investigations on the effect of temperature softening show that the flow parameter’s influence on the effective strain rate is more important than the flow parameter’s direct softening in the flow low alone. The mass flow calculated by the force-balance method is between 87 and 96% of pure plug flow and total discharge is calculated to be 13.3 ± 10 km 3 a -1 . |
format |
Article in Journal/Newspaper |
author |
Armand Høydal, Øyvind |
author_facet |
Armand Høydal, Øyvind |
author_sort |
Armand Høydal, Øyvind |
title |
A force-balance study of ice flow and basal conditions of Jutulstraumen, Antarctica |
title_short |
A force-balance study of ice flow and basal conditions of Jutulstraumen, Antarctica |
title_full |
A force-balance study of ice flow and basal conditions of Jutulstraumen, Antarctica |
title_fullStr |
A force-balance study of ice flow and basal conditions of Jutulstraumen, Antarctica |
title_full_unstemmed |
A force-balance study of ice flow and basal conditions of Jutulstraumen, Antarctica |
title_sort |
force-balance study of ice flow and basal conditions of jutulstraumen, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
1996 |
url |
http://dx.doi.org/10.1017/s0022143000003403 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000003403 |
long_lat |
ENVELOPE(-1.000,-1.000,-72.000,-72.000) |
geographic |
Antarctic The Antarctic Dronning Maud Land West Antarctica Jutulstraumen |
geographic_facet |
Antarctic The Antarctic Dronning Maud Land West Antarctica Jutulstraumen |
genre |
Antarc* Antarctic Antarctica Dronning Maud Land Ice Sheet Journal of Glaciology West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Dronning Maud Land Ice Sheet Journal of Glaciology West Antarctica |
op_source |
Journal of Glaciology volume 42, issue 142, page 413-425 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000003403 |
container_title |
Journal of Glaciology |
container_volume |
42 |
container_issue |
142 |
container_start_page |
413 |
op_container_end_page |
425 |
_version_ |
1792501938090147840 |