Debris entrainment and landform genesis during tidewater glacier surges
Funded by: NERC - Grant Number: NE/I528050/1, and GAINS (Glacial Activity in Neoproterozoic Svalbard) - Grant Number: NE/H004963/1. The englacial entrainment of basal debris during surges presents an opportunity to investigate processes acting at the glacier bed. The subsequent melt-out of debris-ri...
Published in: | Journal of Geophysical Research: Earth Surface |
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Online Access: | http://hdl.handle.net/10023/8275 https://doi.org/10.1002/2015JF003509 |
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ftstandrewserep:oai:research-repository.st-andrews.ac.uk:10023/8275 2023-07-02T03:32:20+02:00 Debris entrainment and landform genesis during tidewater glacier surges Lovell, H. Fleming, E.J. Benn, Doug I Hubbard, B. Lukas, Sven Rea, B.R. Noormets, R. Flink, A.E. University of St Andrews. Geography & Sustainable Development University of St Andrews. Bell-Edwards Geographic Data Institute 2016-02-22 22 application/pdf http://hdl.handle.net/10023/8275 https://doi.org/10.1002/2015JF003509 eng eng Journal of Geophysical Research - Earth Surface Lovell , H , Fleming , E J , Benn , D I , Hubbard , B , Lukas , S , Rea , B R , Noormets , R & Flink , A E 2015 , ' Debris entrainment and landform genesis during tidewater glacier surges ' , Journal of Geophysical Research - Earth Surface , vol. 120 , no. 8 , pp. 1574-1595 . https://doi.org/10.1002/2015JF003509 2169-9003 PURE: 226476735 PURE UUID: 63465a5d-9e21-4b4d-bb03-9259930b247f Scopus: 84941941160 WOS: 000363464000008 ORCID: /0000-0002-3604-0886/work/64697387 http://hdl.handle.net/10023/8275 https://doi.org/10.1002/2015JF003509 ©2015. American Geophysical Union. All Rights Reserved. This work is made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at https://dx.doi.org/10.1002/2015JF003509 Glacier surge Basal ice Debris-rich structures Geometrical ridge networks Svalbard GB Physical geography NDAS GB Journal article 2016 ftstandrewserep https://doi.org/10.1002/2015JF003509 2023-06-13T18:30:24Z Funded by: NERC - Grant Number: NE/I528050/1, and GAINS (Glacial Activity in Neoproterozoic Svalbard) - Grant Number: NE/H004963/1. The englacial entrainment of basal debris during surges presents an opportunity to investigate processes acting at the glacier bed. The subsequent melt-out of debris-rich englacial structures during the quiescent phase produces geometrical ridge networks on glacier forelands that are diagnostic of surge activity. We investigate the link between debris entrainment and proglacial geomorphology by analyzing basal ice, englacial structures, and ridge networks exposed at the margins of Tunabreen, a tidewater surge-type glacier in Svalbard. The basal ice facies display clear evidence for brittle and ductile tectonic deformation, resulting in overall thickening of the basal ice sequence. The formation of debris-poor dispersed facies ice is the result of strain-induced metamorphism of meteoric ice near the bed. Debris-rich englacial structures display a variety of characteristics and morphologies and are interpreted to represent the incorporation and elevation of subglacial till via the squeezing of till into basal crevasses and hydrofracture exploitation of thrust faults, reoriented crevasse squeezes, and preexisting fractures. These structures are observed to melt-out and form embryonic geometrical ridge networks at the base of a terrestrially grounded ice cliff. Ridge networks are also located at the terrestrial margins of Tunabreen, neighboring Von Postbreen, and in a submarine position within Tempelfjorden. Analysis of network characteristics allows these ridges to be linked to different formational mechanisms of their parent debris-rich englacial structures. This in turn provides an insight into variations in the dominant tectonic stress regimes acting across the glacier during surges. Publisher PDF Peer reviewed Article in Journal/Newspaper glacier Svalbard Tempelfjord* Tempelfjorden Tidewater University of St Andrews: Digital Research Repository Svalbard Tempelfjorden ENVELOPE(17.076,17.076,78.404,78.404) Tunabreen ENVELOPE(17.387,17.387,78.461,78.461) Von Postbreen ENVELOPE(17.440,17.440,78.444,78.444) Journal of Geophysical Research: Earth Surface 120 8 1574 1595 |
institution |
Open Polar |
collection |
University of St Andrews: Digital Research Repository |
op_collection_id |
ftstandrewserep |
language |
English |
topic |
Glacier surge Basal ice Debris-rich structures Geometrical ridge networks Svalbard GB Physical geography NDAS GB |
spellingShingle |
Glacier surge Basal ice Debris-rich structures Geometrical ridge networks Svalbard GB Physical geography NDAS GB Lovell, H. Fleming, E.J. Benn, Doug I Hubbard, B. Lukas, Sven Rea, B.R. Noormets, R. Flink, A.E. Debris entrainment and landform genesis during tidewater glacier surges |
topic_facet |
Glacier surge Basal ice Debris-rich structures Geometrical ridge networks Svalbard GB Physical geography NDAS GB |
description |
Funded by: NERC - Grant Number: NE/I528050/1, and GAINS (Glacial Activity in Neoproterozoic Svalbard) - Grant Number: NE/H004963/1. The englacial entrainment of basal debris during surges presents an opportunity to investigate processes acting at the glacier bed. The subsequent melt-out of debris-rich englacial structures during the quiescent phase produces geometrical ridge networks on glacier forelands that are diagnostic of surge activity. We investigate the link between debris entrainment and proglacial geomorphology by analyzing basal ice, englacial structures, and ridge networks exposed at the margins of Tunabreen, a tidewater surge-type glacier in Svalbard. The basal ice facies display clear evidence for brittle and ductile tectonic deformation, resulting in overall thickening of the basal ice sequence. The formation of debris-poor dispersed facies ice is the result of strain-induced metamorphism of meteoric ice near the bed. Debris-rich englacial structures display a variety of characteristics and morphologies and are interpreted to represent the incorporation and elevation of subglacial till via the squeezing of till into basal crevasses and hydrofracture exploitation of thrust faults, reoriented crevasse squeezes, and preexisting fractures. These structures are observed to melt-out and form embryonic geometrical ridge networks at the base of a terrestrially grounded ice cliff. Ridge networks are also located at the terrestrial margins of Tunabreen, neighboring Von Postbreen, and in a submarine position within Tempelfjorden. Analysis of network characteristics allows these ridges to be linked to different formational mechanisms of their parent debris-rich englacial structures. This in turn provides an insight into variations in the dominant tectonic stress regimes acting across the glacier during surges. Publisher PDF Peer reviewed |
author2 |
University of St Andrews. Geography & Sustainable Development University of St Andrews. Bell-Edwards Geographic Data Institute |
format |
Article in Journal/Newspaper |
author |
Lovell, H. Fleming, E.J. Benn, Doug I Hubbard, B. Lukas, Sven Rea, B.R. Noormets, R. Flink, A.E. |
author_facet |
Lovell, H. Fleming, E.J. Benn, Doug I Hubbard, B. Lukas, Sven Rea, B.R. Noormets, R. Flink, A.E. |
author_sort |
Lovell, H. |
title |
Debris entrainment and landform genesis during tidewater glacier surges |
title_short |
Debris entrainment and landform genesis during tidewater glacier surges |
title_full |
Debris entrainment and landform genesis during tidewater glacier surges |
title_fullStr |
Debris entrainment and landform genesis during tidewater glacier surges |
title_full_unstemmed |
Debris entrainment and landform genesis during tidewater glacier surges |
title_sort |
debris entrainment and landform genesis during tidewater glacier surges |
publishDate |
2016 |
url |
http://hdl.handle.net/10023/8275 https://doi.org/10.1002/2015JF003509 |
long_lat |
ENVELOPE(17.076,17.076,78.404,78.404) ENVELOPE(17.387,17.387,78.461,78.461) ENVELOPE(17.440,17.440,78.444,78.444) |
geographic |
Svalbard Tempelfjorden Tunabreen Von Postbreen |
geographic_facet |
Svalbard Tempelfjorden Tunabreen Von Postbreen |
genre |
glacier Svalbard Tempelfjord* Tempelfjorden Tidewater |
genre_facet |
glacier Svalbard Tempelfjord* Tempelfjorden Tidewater |
op_relation |
Journal of Geophysical Research - Earth Surface Lovell , H , Fleming , E J , Benn , D I , Hubbard , B , Lukas , S , Rea , B R , Noormets , R & Flink , A E 2015 , ' Debris entrainment and landform genesis during tidewater glacier surges ' , Journal of Geophysical Research - Earth Surface , vol. 120 , no. 8 , pp. 1574-1595 . https://doi.org/10.1002/2015JF003509 2169-9003 PURE: 226476735 PURE UUID: 63465a5d-9e21-4b4d-bb03-9259930b247f Scopus: 84941941160 WOS: 000363464000008 ORCID: /0000-0002-3604-0886/work/64697387 http://hdl.handle.net/10023/8275 https://doi.org/10.1002/2015JF003509 |
op_rights |
©2015. American Geophysical Union. All Rights Reserved. This work is made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at https://dx.doi.org/10.1002/2015JF003509 |
op_doi |
https://doi.org/10.1002/2015JF003509 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
120 |
container_issue |
8 |
container_start_page |
1574 |
op_container_end_page |
1595 |
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1770271877110956032 |