Ice deformation at the confluence of two glaciers investigated with conceptual map-plane and flowline models
Abstract Using analytical and numerical techniques, a two-dimensional (2-D) map-plane model and a 2-D flowline model are utilized to elucidate the horizontal and vertical ice deformation at the confluence of two glaciers. For a perfectly symmetrical confluence, the junction point of the two tributar...
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Cambridge University Press (CUP)
1997
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Online Access: | http://dx.doi.org/10.1017/s0022143000035140 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000035140 |
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crcambridgeupr:10.1017/s0022143000035140 2024-03-03T08:46:09+00:00 Ice deformation at the confluence of two glaciers investigated with conceptual map-plane and flowline models Gudmundsson, G. Hilmar 1997 http://dx.doi.org/10.1017/s0022143000035140 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000035140 en eng Cambridge University Press (CUP) Journal of Glaciology volume 43, issue 145, page 537-547 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1997 crcambridgeupr https://doi.org/10.1017/s0022143000035140 2024-02-08T08:40:23Z Abstract Using analytical and numerical techniques, a two-dimensional (2-D) map-plane model and a 2-D flowline model are utilized to elucidate the horizontal and vertical ice deformation at the confluence of two glaciers. For a perfectly symmetrical confluence, the junction point of the two tributaries can be modeled as a no-slip/free-slip transition. A strongly localized surface depression develops around the junction point, accompanied by two broadly elevated zones positioned close to the margins of the tributaries facing the junction point. The confluence center line is subjected to horizontal longitudinal extension and a transverse compression. The compression generally exceeds the concomitant longitudinal extension in magnitude. Depth-integrated vertical strain rates along the center line are positive (extension), but the strain-rate variation with depth depends critically on the type of basal boundary conditions at the glacier bed. For a no-slip boundary condition, vertical strain rates change from positive at the surface to negative close to the base, whereas for a free-slip boundary condition (perfect sliding) vertical strain rates are positive throughout the depth. These theoretical results are compared with field measurements from Unteraargletscher, Bernese Alps, Switzerland. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 43 145 537 547 |
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Open Polar |
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Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Gudmundsson, G. Hilmar Ice deformation at the confluence of two glaciers investigated with conceptual map-plane and flowline models |
topic_facet |
Earth-Surface Processes |
description |
Abstract Using analytical and numerical techniques, a two-dimensional (2-D) map-plane model and a 2-D flowline model are utilized to elucidate the horizontal and vertical ice deformation at the confluence of two glaciers. For a perfectly symmetrical confluence, the junction point of the two tributaries can be modeled as a no-slip/free-slip transition. A strongly localized surface depression develops around the junction point, accompanied by two broadly elevated zones positioned close to the margins of the tributaries facing the junction point. The confluence center line is subjected to horizontal longitudinal extension and a transverse compression. The compression generally exceeds the concomitant longitudinal extension in magnitude. Depth-integrated vertical strain rates along the center line are positive (extension), but the strain-rate variation with depth depends critically on the type of basal boundary conditions at the glacier bed. For a no-slip boundary condition, vertical strain rates change from positive at the surface to negative close to the base, whereas for a free-slip boundary condition (perfect sliding) vertical strain rates are positive throughout the depth. These theoretical results are compared with field measurements from Unteraargletscher, Bernese Alps, Switzerland. |
format |
Article in Journal/Newspaper |
author |
Gudmundsson, G. Hilmar |
author_facet |
Gudmundsson, G. Hilmar |
author_sort |
Gudmundsson, G. Hilmar |
title |
Ice deformation at the confluence of two glaciers investigated with conceptual map-plane and flowline models |
title_short |
Ice deformation at the confluence of two glaciers investigated with conceptual map-plane and flowline models |
title_full |
Ice deformation at the confluence of two glaciers investigated with conceptual map-plane and flowline models |
title_fullStr |
Ice deformation at the confluence of two glaciers investigated with conceptual map-plane and flowline models |
title_full_unstemmed |
Ice deformation at the confluence of two glaciers investigated with conceptual map-plane and flowline models |
title_sort |
ice deformation at the confluence of two glaciers investigated with conceptual map-plane and flowline models |
publisher |
Cambridge University Press (CUP) |
publishDate |
1997 |
url |
http://dx.doi.org/10.1017/s0022143000035140 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000035140 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 43, issue 145, page 537-547 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000035140 |
container_title |
Journal of Glaciology |
container_volume |
43 |
container_issue |
145 |
container_start_page |
537 |
op_container_end_page |
547 |
_version_ |
1792502133673689088 |