Size, Shape and Spatial Arrangement of Mega-scale Glacial Lineations from a Large and Diverse Dataset
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 characterization o...
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ftunisfloridatam:oai:digitalcommons.usf.edu:msc_facpub-2561 2023-05-15T14:04:11+02:00 Size, Shape and Spatial Arrangement of Mega-scale Glacial Lineations from a Large and Diverse Dataset Spagnolo, Matteo Clark, Chris D. Ely, Jeremy C. Stokes, Chris R. Anderson, John B. Andreassen, Karin Graham, Alastair G. C. King, Edward C. 2014-01-01T08:00:00Z application/pdf https://digitalcommons.usf.edu/msc_facpub/1549 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2561&context=msc_facpub unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/1549 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2561&context=msc_facpub http://creativecommons.org/licenses/by/3.0/ CC-BY Marine Science Faculty Publications MSGL glacial bedform ice stream morphometry Life Sciences article 2014 ftunisfloridatam 2022-01-20T18:40:25Z 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 characterization 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 characterized by an exceptional parallel conformity (80% of all mapped MSGLs have an azimuth within 5° 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-organized 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 with 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 Digital Commons University of South Florida (USF) West Antarctica Canada Norway |
institution |
Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
MSGL glacial bedform ice stream morphometry Life Sciences |
spellingShingle |
MSGL glacial bedform ice stream morphometry Life Sciences 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 from a Large and Diverse Dataset |
topic_facet |
MSGL glacial bedform ice stream morphometry Life Sciences |
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 characterization 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 characterized by an exceptional parallel conformity (80% of all mapped MSGLs have an azimuth within 5° 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-organized 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 with 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. |
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 from a Large and Diverse Dataset |
title_short |
Size, Shape and Spatial Arrangement of Mega-scale Glacial Lineations from a Large and Diverse Dataset |
title_full |
Size, Shape and Spatial Arrangement of Mega-scale Glacial Lineations from a Large and Diverse Dataset |
title_fullStr |
Size, Shape and Spatial Arrangement of Mega-scale Glacial Lineations from a Large and Diverse Dataset |
title_full_unstemmed |
Size, Shape and Spatial Arrangement of Mega-scale Glacial Lineations from a Large and Diverse Dataset |
title_sort |
size, shape and spatial arrangement of mega-scale glacial lineations from a large and diverse dataset |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2014 |
url |
https://digitalcommons.usf.edu/msc_facpub/1549 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2561&context=msc_facpub |
geographic |
West Antarctica Canada Norway |
geographic_facet |
West Antarctica Canada Norway |
genre |
Antarc* Antarctica West Antarctica |
genre_facet |
Antarc* Antarctica West Antarctica |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/1549 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2561&context=msc_facpub |
op_rights |
http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
_version_ |
1766275210115284992 |