Flow and structure in a dendritic glacier with bedrock steps
We analyse ice flow and structural glaciology of Shackleton Glacier, a dendritic glacier with multiple icefalls in the Canadian Rockies. A major tributary-trunk junction allows us to investigate the potential of tributaries to alter trunk flow and structure, and the formation of bedrock steps at con...
Published in: | Journal of Glaciology |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Cambridge University Press
2017
|
Subjects: | |
Online Access: | https://doi.org/10.1017/jog.2017.58 https://doaj.org/article/27854bb79c7242edbe499614c546d090 |
id |
ftdoajarticles:oai:doaj.org/article:27854bb79c7242edbe499614c546d090 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:27854bb79c7242edbe499614c546d090 2023-05-15T16:57:36+02:00 Flow and structure in a dendritic glacier with bedrock steps HESTER JISKOOT THOMAS A FOX WESLEY VAN WYCHEN 2017-10-01T00:00:00Z https://doi.org/10.1017/jog.2017.58 https://doaj.org/article/27854bb79c7242edbe499614c546d090 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143017000582/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2017.58 0022-1430 1727-5652 https://doaj.org/article/27854bb79c7242edbe499614c546d090 Journal of Glaciology, Vol 63, Pp 912-928 (2017) glacier flow glacier erosion glacier surges mountain glaciers structural glaciology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2017 ftdoajarticles https://doi.org/10.1017/jog.2017.58 2023-03-12T01:30:59Z We analyse ice flow and structural glaciology of Shackleton Glacier, a dendritic glacier with multiple icefalls in the Canadian Rockies. A major tributary-trunk junction allows us to investigate the potential of tributaries to alter trunk flow and structure, and the formation of bedrock steps at confluences. Multi-year velocity-stake data and structural glaciology up-glacier from the junction were assimilated with glacier-wide velocity derived from Radarsat-2 speckle tracking. Maximum flow speeds are 65 m a−1 in the trunk and 175 m a−1 in icefalls. Field and remote-sensing velocities are in good agreement, except where velocity gradients are high. Although compression occurs in the trunk up-glacier of the tributary entrance, glacier flux is steady state because flow speed increases at the junction due to the funnelling of trunk ice towards an icefall related to a bedrock step. Drawing on a published erosion model, we relate the heights of the step and the hanging valley to the relative fluxes of the tributary and trunk. It is the first time that an extant glacier is used to test and support such model. Our study elucidates the inherent complexity of tributary/trunk interactions and provides a conceptual model for trunk flow restriction by a tributary in surge-type glaciers. Article in Journal/Newspaper Journal of Glaciology Shackleton Glacier Directory of Open Access Journals: DOAJ Articles Shackleton Shackleton Glacier ENVELOPE(-37.200,-37.200,-54.133,-54.133) Journal of Glaciology 63 241 912 928 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
glacier flow glacier erosion glacier surges mountain glaciers structural glaciology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
glacier flow glacier erosion glacier surges mountain glaciers structural glaciology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 HESTER JISKOOT THOMAS A FOX WESLEY VAN WYCHEN Flow and structure in a dendritic glacier with bedrock steps |
topic_facet |
glacier flow glacier erosion glacier surges mountain glaciers structural glaciology Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
We analyse ice flow and structural glaciology of Shackleton Glacier, a dendritic glacier with multiple icefalls in the Canadian Rockies. A major tributary-trunk junction allows us to investigate the potential of tributaries to alter trunk flow and structure, and the formation of bedrock steps at confluences. Multi-year velocity-stake data and structural glaciology up-glacier from the junction were assimilated with glacier-wide velocity derived from Radarsat-2 speckle tracking. Maximum flow speeds are 65 m a−1 in the trunk and 175 m a−1 in icefalls. Field and remote-sensing velocities are in good agreement, except where velocity gradients are high. Although compression occurs in the trunk up-glacier of the tributary entrance, glacier flux is steady state because flow speed increases at the junction due to the funnelling of trunk ice towards an icefall related to a bedrock step. Drawing on a published erosion model, we relate the heights of the step and the hanging valley to the relative fluxes of the tributary and trunk. It is the first time that an extant glacier is used to test and support such model. Our study elucidates the inherent complexity of tributary/trunk interactions and provides a conceptual model for trunk flow restriction by a tributary in surge-type glaciers. |
format |
Article in Journal/Newspaper |
author |
HESTER JISKOOT THOMAS A FOX WESLEY VAN WYCHEN |
author_facet |
HESTER JISKOOT THOMAS A FOX WESLEY VAN WYCHEN |
author_sort |
HESTER JISKOOT |
title |
Flow and structure in a dendritic glacier with bedrock steps |
title_short |
Flow and structure in a dendritic glacier with bedrock steps |
title_full |
Flow and structure in a dendritic glacier with bedrock steps |
title_fullStr |
Flow and structure in a dendritic glacier with bedrock steps |
title_full_unstemmed |
Flow and structure in a dendritic glacier with bedrock steps |
title_sort |
flow and structure in a dendritic glacier with bedrock steps |
publisher |
Cambridge University Press |
publishDate |
2017 |
url |
https://doi.org/10.1017/jog.2017.58 https://doaj.org/article/27854bb79c7242edbe499614c546d090 |
long_lat |
ENVELOPE(-37.200,-37.200,-54.133,-54.133) |
geographic |
Shackleton Shackleton Glacier |
geographic_facet |
Shackleton Shackleton Glacier |
genre |
Journal of Glaciology Shackleton Glacier |
genre_facet |
Journal of Glaciology Shackleton Glacier |
op_source |
Journal of Glaciology, Vol 63, Pp 912-928 (2017) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143017000582/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2017.58 0022-1430 1727-5652 https://doaj.org/article/27854bb79c7242edbe499614c546d090 |
op_doi |
https://doi.org/10.1017/jog.2017.58 |
container_title |
Journal of Glaciology |
container_volume |
63 |
container_issue |
241 |
container_start_page |
912 |
op_container_end_page |
928 |
_version_ |
1766049158202916864 |