Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland
This paper investigates the controls on the formation of subglacially eroded bedrock bedforms beneath the topographically confined region upstream of the Uummannaq Ice Stream (UIS). During the last glacial cycle, palaeoglaciological conditions are believed to have been similar for all sites in the s...
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Online Access: | https://www.zora.uzh.ch/id/eprint/136092/ https://www.zora.uzh.ch/id/eprint/136092/1/2015_Vieli_1-s2.0-S0169555X14006217-main.pdf https://doi.org/10.5167/uzh-136092 https://doi.org/10.1016/j.geomorph.2014.12.019 |
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ftunivzuerich:oai:www.zora.uzh.ch:136092 2024-09-30T14:35:58+00:00 Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland Lane, Timothy P Roberts, David H Rea, Brice R Ó Cofaigh, Colm Vieli, Andreas 2015 application/pdf https://www.zora.uzh.ch/id/eprint/136092/ https://www.zora.uzh.ch/id/eprint/136092/1/2015_Vieli_1-s2.0-S0169555X14006217-main.pdf https://doi.org/10.5167/uzh-136092 https://doi.org/10.1016/j.geomorph.2014.12.019 eng eng Elsevier https://www.zora.uzh.ch/id/eprint/136092/1/2015_Vieli_1-s2.0-S0169555X14006217-main.pdf doi:10.5167/uzh-136092 doi:10.1016/j.geomorph.2014.12.019 urn:issn:0169-555X info:eu-repo/semantics/restrictedAccess Lane, Timothy P; Roberts, David H; Rea, Brice R; Ó Cofaigh, Colm; Vieli, Andreas (2015). Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland. Geomorphology, 231:301-313. Institute of Geography 910 Geography & travel Journal Article PeerReviewed info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2015 ftunivzuerich https://doi.org/10.5167/uzh-13609210.1016/j.geomorph.2014.12.019 2024-09-18T00:49:48Z This paper investigates the controls on the formation of subglacially eroded bedrock bedforms beneath the topographically confined region upstream of the Uummannaq Ice Stream (UIS). During the last glacial cycle, palaeoglaciological conditions are believed to have been similar for all sites in the study, characterised by thick, fast-flowing ice moving over a rigid bedrock bed. Classic bedrock bedforms indicative of glacially eroded terrain were mapped, including p-forms, roches moutonnées, and whalebacks. Bedform long axes and plucked face orientations display close correlation (parallel and perpendicular) to palaeo-ice flow directions inferred from striae measurements. Across all sites, elongation ratios (length to width) varied by an order of magnitude between 0.8:1 and 8.4:1. Bedform properties (length, height, width, and long axis orientation) from four subsample areas, form morphometrically distinct populations, despite their close proximity and hypothesised similarity in palaeoglaciological conditions. Variations in lithology and geological structures (e.g., joint frequency; joint dip; joint orientation; bedding plane thickness; and bedding plane dip) provide lines of geological weakness, which focus the glacial erosion, in turn controlling bedform geometries. Determining the relationship (s) between bedding plane dip relative to palaeo-ice flow and bedform shape, relative length, amplitude, and wavelength has important ramifications for understanding subglacial bed roughness, cavity formation, and likely erosion style (quarrying and/or abrasion) at the ice-bed interface. This paper demonstrates a direct link between bedrock bedform geometries and geological structure and emphasises the need to understand bedrock bedform characteristics when reconstructing palaeoglaciological conditions. Article in Journal/Newspaper Greenland Uummannaq University of Zurich (UZH): ZORA (Zurich Open Repository and Archive Greenland Uis ENVELOPE(141.975,141.975,60.184,60.184) |
institution |
Open Polar |
collection |
University of Zurich (UZH): ZORA (Zurich Open Repository and Archive |
op_collection_id |
ftunivzuerich |
language |
English |
topic |
Institute of Geography 910 Geography & travel |
spellingShingle |
Institute of Geography 910 Geography & travel Lane, Timothy P Roberts, David H Rea, Brice R Ó Cofaigh, Colm Vieli, Andreas Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland |
topic_facet |
Institute of Geography 910 Geography & travel |
description |
This paper investigates the controls on the formation of subglacially eroded bedrock bedforms beneath the topographically confined region upstream of the Uummannaq Ice Stream (UIS). During the last glacial cycle, palaeoglaciological conditions are believed to have been similar for all sites in the study, characterised by thick, fast-flowing ice moving over a rigid bedrock bed. Classic bedrock bedforms indicative of glacially eroded terrain were mapped, including p-forms, roches moutonnées, and whalebacks. Bedform long axes and plucked face orientations display close correlation (parallel and perpendicular) to palaeo-ice flow directions inferred from striae measurements. Across all sites, elongation ratios (length to width) varied by an order of magnitude between 0.8:1 and 8.4:1. Bedform properties (length, height, width, and long axis orientation) from four subsample areas, form morphometrically distinct populations, despite their close proximity and hypothesised similarity in palaeoglaciological conditions. Variations in lithology and geological structures (e.g., joint frequency; joint dip; joint orientation; bedding plane thickness; and bedding plane dip) provide lines of geological weakness, which focus the glacial erosion, in turn controlling bedform geometries. Determining the relationship (s) between bedding plane dip relative to palaeo-ice flow and bedform shape, relative length, amplitude, and wavelength has important ramifications for understanding subglacial bed roughness, cavity formation, and likely erosion style (quarrying and/or abrasion) at the ice-bed interface. This paper demonstrates a direct link between bedrock bedform geometries and geological structure and emphasises the need to understand bedrock bedform characteristics when reconstructing palaeoglaciological conditions. |
format |
Article in Journal/Newspaper |
author |
Lane, Timothy P Roberts, David H Rea, Brice R Ó Cofaigh, Colm Vieli, Andreas |
author_facet |
Lane, Timothy P Roberts, David H Rea, Brice R Ó Cofaigh, Colm Vieli, Andreas |
author_sort |
Lane, Timothy P |
title |
Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland |
title_short |
Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland |
title_full |
Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland |
title_fullStr |
Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland |
title_full_unstemmed |
Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland |
title_sort |
controls on bedrock bedform development beneath the uummannaq ice stream onset zone, west greenland |
publisher |
Elsevier |
publishDate |
2015 |
url |
https://www.zora.uzh.ch/id/eprint/136092/ https://www.zora.uzh.ch/id/eprint/136092/1/2015_Vieli_1-s2.0-S0169555X14006217-main.pdf https://doi.org/10.5167/uzh-136092 https://doi.org/10.1016/j.geomorph.2014.12.019 |
long_lat |
ENVELOPE(141.975,141.975,60.184,60.184) |
geographic |
Greenland Uis |
geographic_facet |
Greenland Uis |
genre |
Greenland Uummannaq |
genre_facet |
Greenland Uummannaq |
op_source |
Lane, Timothy P; Roberts, David H; Rea, Brice R; Ó Cofaigh, Colm; Vieli, Andreas (2015). Controls on bedrock bedform development beneath the Uummannaq Ice Stream onset zone, West Greenland. Geomorphology, 231:301-313. |
op_relation |
https://www.zora.uzh.ch/id/eprint/136092/1/2015_Vieli_1-s2.0-S0169555X14006217-main.pdf doi:10.5167/uzh-136092 doi:10.1016/j.geomorph.2014.12.019 urn:issn:0169-555X |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.5167/uzh-13609210.1016/j.geomorph.2014.12.019 |
_version_ |
1811639167690473472 |