Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes
Mega-scale glacial lineations (MSGLs) are a characteristic landform on ice stream beds. Solving the puzzle of their formation is key to understanding how ice interacts with its bed and how this, in turn, influences the dynamics of ice streams. However, a comprehensive and detailed characterisation o...
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ftnerc:oai:nora.nerc.ac.uk:500440 2023-05-15T13:48:07+02:00 Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes Spagnolo, Matteo Clark, Chris D. Ely, Jeremy C. Stokes, Chris R. Anderson, John B. Andreassen, Karin Graham, Alastair G.C. King, Edward C. 2014-09-15 text http://nora.nerc.ac.uk/id/eprint/500440/ https://nora.nerc.ac.uk/id/eprint/500440/1/esp3532.pdf en eng Wiley https://nora.nerc.ac.uk/id/eprint/500440/1/esp3532.pdf Spagnolo, Matteo; Clark, Chris D.; Ely, Jeremy C.; Stokes, Chris R.; Anderson, John B.; Andreassen, Karin; Graham, Alastair G.C.; King, Edward C. orcid:0000-0003-3793-3915 . 2014 Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes. Earth Surface Processes and Landforms, 39 (11). 1432-1448. https://doi.org/10.1002/esp.3532 <https://doi.org/10.1002/esp.3532> cc_by CC-BY Publication - Article PeerReviewed 2014 ftnerc https://doi.org/10.1002/esp.3532 2023-02-04T19:36:21Z Mega-scale glacial lineations (MSGLs) are a characteristic landform on ice stream beds. Solving the puzzle of their formation is key to understanding how ice interacts with its bed and how this, in turn, influences the dynamics of ice streams. However, a comprehensive and detailed characterisation of this landform's size, shape and spatial arrangement, which might serve to test and refine formational theories, is largely lacking. This paper presents a detailed morphometric analysis and comparison of 4043 MSGLs from eight palaeo-ice stream settings: three offshore (Norway and Antarctica), four onshore (Canada), and one from under a modern ice stream in West Antarctica. The length of MSGLs is lower than previously suggested (mode 1000-2000 m; median 2892 m), and they initiate and terminate at various locations on an ice stream bed. Their spatial arrangement reveals a pattern that is characterised by an exceptional parallel conformity (80% of all mapped MSGLs have an azimuth within 5 degrees from the mean values), and a fairly constant lateral spacing (mode 200-300 m; median 330 m), which we interpret as an indication that MSGLs are a spatially self-organised phenomenon. Results show that size, shape and spatial arrangement of MSGLs are consistent both within and also generally between different ice stream beds. We suggest this results from a common mechanism of formation, which is largely insensitive to local factors. Although the elongation of MSGLs (mode 6-8; median 12.2) is typically higher than features described as drumlins, these values and those of their width (mode 100-200 m; median 268 m) overlap, which suggests the two landforms are part of a morphological continuum and may share a similar origin. We compare their morphometry to explicit predictions made by the groove-ploughing and rilling instability theories of MSGL formation. Although the latter was most compatible, neither is fully supported by observations. Article in Journal/Newspaper Antarc* Antarctica West Antarctica Natural Environment Research Council: NERC Open Research Archive West Antarctica Canada Norway Earth Surface Processes and Landforms n/a n/a |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Mega-scale glacial lineations (MSGLs) are a characteristic landform on ice stream beds. Solving the puzzle of their formation is key to understanding how ice interacts with its bed and how this, in turn, influences the dynamics of ice streams. However, a comprehensive and detailed characterisation of this landform's size, shape and spatial arrangement, which might serve to test and refine formational theories, is largely lacking. This paper presents a detailed morphometric analysis and comparison of 4043 MSGLs from eight palaeo-ice stream settings: three offshore (Norway and Antarctica), four onshore (Canada), and one from under a modern ice stream in West Antarctica. The length of MSGLs is lower than previously suggested (mode 1000-2000 m; median 2892 m), and they initiate and terminate at various locations on an ice stream bed. Their spatial arrangement reveals a pattern that is characterised by an exceptional parallel conformity (80% of all mapped MSGLs have an azimuth within 5 degrees from the mean values), and a fairly constant lateral spacing (mode 200-300 m; median 330 m), which we interpret as an indication that MSGLs are a spatially self-organised phenomenon. Results show that size, shape and spatial arrangement of MSGLs are consistent both within and also generally between different ice stream beds. We suggest this results from a common mechanism of formation, which is largely insensitive to local factors. Although the elongation of MSGLs (mode 6-8; median 12.2) is typically higher than features described as drumlins, these values and those of their width (mode 100-200 m; median 268 m) overlap, which suggests the two landforms are part of a morphological continuum and may share a similar origin. We compare their morphometry to explicit predictions made by the groove-ploughing and rilling instability theories of MSGL formation. Although the latter was most compatible, neither is fully supported by observations. |
format |
Article in Journal/Newspaper |
author |
Spagnolo, Matteo Clark, Chris D. Ely, Jeremy C. Stokes, Chris R. Anderson, John B. Andreassen, Karin Graham, Alastair G.C. King, Edward C. |
spellingShingle |
Spagnolo, Matteo Clark, Chris D. Ely, Jeremy C. Stokes, Chris R. Anderson, John B. Andreassen, Karin Graham, Alastair G.C. King, Edward C. Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes |
author_facet |
Spagnolo, Matteo Clark, Chris D. Ely, Jeremy C. Stokes, Chris R. Anderson, John B. Andreassen, Karin Graham, Alastair G.C. King, Edward C. |
author_sort |
Spagnolo, Matteo |
title |
Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes |
title_short |
Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes |
title_full |
Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes |
title_fullStr |
Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes |
title_full_unstemmed |
Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes |
title_sort |
size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes |
publisher |
Wiley |
publishDate |
2014 |
url |
http://nora.nerc.ac.uk/id/eprint/500440/ https://nora.nerc.ac.uk/id/eprint/500440/1/esp3532.pdf |
geographic |
West Antarctica Canada Norway |
geographic_facet |
West Antarctica Canada Norway |
genre |
Antarc* Antarctica West Antarctica |
genre_facet |
Antarc* Antarctica West Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/500440/1/esp3532.pdf Spagnolo, Matteo; Clark, Chris D.; Ely, Jeremy C.; Stokes, Chris R.; Anderson, John B.; Andreassen, Karin; Graham, Alastair G.C.; King, Edward C. orcid:0000-0003-3793-3915 . 2014 Size, shape and spatial arrangement of mega-scale glacial lineations, and implications for ice stream basal processes. Earth Surface Processes and Landforms, 39 (11). 1432-1448. https://doi.org/10.1002/esp.3532 <https://doi.org/10.1002/esp.3532> |
op_rights |
cc_by |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1002/esp.3532 |
container_title |
Earth Surface Processes and Landforms |
container_start_page |
n/a |
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n/a |
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1766248632241094656 |