Longitudinal Variations in Glacial Flow: Theory and Test Using Data from the Byrd Station Strain Network, Antarctica
Abstract A theory advanced by Budd (1970) for ice-flow variation due to bed effects is improved and applied to the flow of the ice sheet leading to Byrd Station, Antarctica. Linear viscous rheology is used and a biharmonic equation for stress and strain-rate variation is solved. Basal boundary condi...
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Language: | English |
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Cambridge University Press (CUP)
1983
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Online Access: | http://dx.doi.org/10.1017/s0022143000005165 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005165 |
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crcambridgeupr:10.1017/s0022143000005165 2024-03-03T08:38:46+00:00 Longitudinal Variations in Glacial Flow: Theory and Test Using Data from the Byrd Station Strain Network, Antarctica Whillans, I. M. Johnsen, S. J. 1983 http://dx.doi.org/10.1017/s0022143000005165 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005165 en eng Cambridge University Press (CUP) Journal of Glaciology volume 29, issue 101, page 78-97 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1983 crcambridgeupr https://doi.org/10.1017/s0022143000005165 2024-02-08T08:40:23Z Abstract A theory advanced by Budd (1970) for ice-flow variation due to bed effects is improved and applied to the flow of the ice sheet leading to Byrd Station, Antarctica. Linear viscous rheology is used and a biharmonic equation for stress and strain-rate variation is solved. Basal boundary conditions include an undulating bottom topography and longitudinal variations in basal sliding and shear stress. Near Byrd Station it is found that variations in basal sliding and shear stress have more important direct effects than does the bed topography. This result is important to considerations on the stability of glacial flow. Distortions of internal layers are calculated and these closely match the distortions observed in the internal layers detected by the NSF-SPRI-TUD radar. The phase relationship between internal layer distortion and surface topography provides a positive test for the theory. The theory does not predict a spectral power maximum in surface topographic relief at a wavelength of three ice thicknesses. Such wavelengths however dominate and we speculate that this may be due to the dynamics of glacial erosion and deposition or with subglacial water motion. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Journal of Glaciology Cambridge University Press Byrd Byrd Station ENVELOPE(-119.533,-119.533,-80.017,-80.017) Journal of Glaciology 29 101 78 97 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Whillans, I. M. Johnsen, S. J. Longitudinal Variations in Glacial Flow: Theory and Test Using Data from the Byrd Station Strain Network, Antarctica |
topic_facet |
Earth-Surface Processes |
description |
Abstract A theory advanced by Budd (1970) for ice-flow variation due to bed effects is improved and applied to the flow of the ice sheet leading to Byrd Station, Antarctica. Linear viscous rheology is used and a biharmonic equation for stress and strain-rate variation is solved. Basal boundary conditions include an undulating bottom topography and longitudinal variations in basal sliding and shear stress. Near Byrd Station it is found that variations in basal sliding and shear stress have more important direct effects than does the bed topography. This result is important to considerations on the stability of glacial flow. Distortions of internal layers are calculated and these closely match the distortions observed in the internal layers detected by the NSF-SPRI-TUD radar. The phase relationship between internal layer distortion and surface topography provides a positive test for the theory. The theory does not predict a spectral power maximum in surface topographic relief at a wavelength of three ice thicknesses. Such wavelengths however dominate and we speculate that this may be due to the dynamics of glacial erosion and deposition or with subglacial water motion. |
format |
Article in Journal/Newspaper |
author |
Whillans, I. M. Johnsen, S. J. |
author_facet |
Whillans, I. M. Johnsen, S. J. |
author_sort |
Whillans, I. M. |
title |
Longitudinal Variations in Glacial Flow: Theory and Test Using Data from the Byrd Station Strain Network, Antarctica |
title_short |
Longitudinal Variations in Glacial Flow: Theory and Test Using Data from the Byrd Station Strain Network, Antarctica |
title_full |
Longitudinal Variations in Glacial Flow: Theory and Test Using Data from the Byrd Station Strain Network, Antarctica |
title_fullStr |
Longitudinal Variations in Glacial Flow: Theory and Test Using Data from the Byrd Station Strain Network, Antarctica |
title_full_unstemmed |
Longitudinal Variations in Glacial Flow: Theory and Test Using Data from the Byrd Station Strain Network, Antarctica |
title_sort |
longitudinal variations in glacial flow: theory and test using data from the byrd station strain network, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
1983 |
url |
http://dx.doi.org/10.1017/s0022143000005165 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000005165 |
long_lat |
ENVELOPE(-119.533,-119.533,-80.017,-80.017) |
geographic |
Byrd Byrd Station |
geographic_facet |
Byrd Byrd Station |
genre |
Antarc* Antarctica Ice Sheet Journal of Glaciology |
genre_facet |
Antarc* Antarctica Ice Sheet Journal of Glaciology |
op_source |
Journal of Glaciology volume 29, issue 101, page 78-97 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000005165 |
container_title |
Journal of Glaciology |
container_volume |
29 |
container_issue |
101 |
container_start_page |
78 |
op_container_end_page |
97 |
_version_ |
1792507212804915200 |