Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica
This work is ITGC Contribution No. ITGC-036 and is an output from the Thwaites Interdisciplinary Margin Evolution (TIME) project as part of the International Thwaites Glacier Collaboration (ITGC), supported by Natural Environment Research Council (NERC) research grant #NE/S006788/1 supporting T. J....
Published in: | Journal of Geophysical Research: Earth Surface |
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Online Access: | http://hdl.handle.net/10023/27405 https://doi.org/10.1029/2020jf006023 |
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ftstandrewserep:oai:research-repository.st-andrews.ac.uk:10023/27405 2023-07-02T03:30:38+02:00 Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica Young, T. J. Schroeder, D. M. Jordan, T. M. Christoffersen, P. Tulaczyk, S. M. Culberg, R. Bienert, N. L. University of St Andrews. School of Geography & Sustainable Development 2023-04-17T10:30:05Z 26 application/pdf http://hdl.handle.net/10023/27405 https://doi.org/10.1029/2020jf006023 eng eng Journal of Geophysical Research: Earth Surface Young , T J , Schroeder , D M , Jordan , T M , Christoffersen , P , Tulaczyk , S M , Culberg , R & Bienert , N L 2021 , ' Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica ' , Journal of Geophysical Research: Earth Surface , vol. 126 , no. 5 . https://doi.org/10.1029/2020jf006023 2169-9011 PURE: 284141722 PURE UUID: 5e655a40-3ba1-4a56-9240-86dcd734ef4b Bibtex: Young_2021 ORCID: /0000-0001-5865-3459/work/133734041 http://hdl.handle.net/10023/27405 https://doi.org/10.1029/2020jf006023 Copyright © 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Ice penetrating radar Polarimetry Antarctica Birefringence Fabric Glaciology 3rd-DAS MCP Journal article 2023 ftstandrewserep https://doi.org/10.1029/2020jf006023 2023-06-13T18:26:10Z This work is ITGC Contribution No. ITGC-036 and is an output from the Thwaites Interdisciplinary Margin Evolution (TIME) project as part of the International Thwaites Glacier Collaboration (ITGC), supported by Natural Environment Research Council (NERC) research grant #NE/S006788/1 supporting T. J. Young and P. Christoffersen, and National Science Foundation (NSF) research grant #1739027 supporting S. M. Tulaczyk and D. M. Schroeder. Logistics for this project were provided by the NSF-U.S. Antarctic Program and NERC-British Antarctic Survey. R. Culberg is supported by a USA Department of Defense NDSEG Fellowship and N. L. Bienert is supported by an NSF Graduate Research Fellowship. In airborne radargrams, undulating periodic patterns in amplitude that overprint traditional radiostratigraphic layering are occasionally observed, however, they have yet to be analyzed from a geophysical or glaciological perspective. We present evidence supported by theory that these depth-periodic patterns are consistent with a modulation of the received radar power due to the birefringence of polar ice, and therefore indicate the presence of bulk fabric anisotropy. Here, we investigate the periodic component of birefringence-induced radar power recorded in airborne radar data at the eastern shear margin of Thwaites Glacier and quantify the lateral variation in azimuthal fabric strength across this margin. We find the depth variability of birefringence periodicity crossing the shear margin to be a visual expression of its shear state and its development, which appears consistent with present-day ice deformation. The morphology of the birefringent patterns is centered at the location of maximum shear and observed in all cross-margin profiles, consistent with predictions of ice fabric when subjected to simple shear. The englacial fabric appears stronger inside the ice stream than outward of the shear margin. The detection of birefringent periodicity from non-polarimetric radargrams presents a novel use of subsurface radar to ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Antarctica Journal British Antarctic Survey Thwaites Glacier West Antarctica University of St Andrews: Digital Research Repository Antarctic Christoffersen ENVELOPE(-45.050,-45.050,-60.733,-60.733) Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) West Antarctica Journal of Geophysical Research: Earth Surface 126 5 |
institution |
Open Polar |
collection |
University of St Andrews: Digital Research Repository |
op_collection_id |
ftstandrewserep |
language |
English |
topic |
Ice penetrating radar Polarimetry Antarctica Birefringence Fabric Glaciology 3rd-DAS MCP |
spellingShingle |
Ice penetrating radar Polarimetry Antarctica Birefringence Fabric Glaciology 3rd-DAS MCP Young, T. J. Schroeder, D. M. Jordan, T. M. Christoffersen, P. Tulaczyk, S. M. Culberg, R. Bienert, N. L. Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica |
topic_facet |
Ice penetrating radar Polarimetry Antarctica Birefringence Fabric Glaciology 3rd-DAS MCP |
description |
This work is ITGC Contribution No. ITGC-036 and is an output from the Thwaites Interdisciplinary Margin Evolution (TIME) project as part of the International Thwaites Glacier Collaboration (ITGC), supported by Natural Environment Research Council (NERC) research grant #NE/S006788/1 supporting T. J. Young and P. Christoffersen, and National Science Foundation (NSF) research grant #1739027 supporting S. M. Tulaczyk and D. M. Schroeder. Logistics for this project were provided by the NSF-U.S. Antarctic Program and NERC-British Antarctic Survey. R. Culberg is supported by a USA Department of Defense NDSEG Fellowship and N. L. Bienert is supported by an NSF Graduate Research Fellowship. In airborne radargrams, undulating periodic patterns in amplitude that overprint traditional radiostratigraphic layering are occasionally observed, however, they have yet to be analyzed from a geophysical or glaciological perspective. We present evidence supported by theory that these depth-periodic patterns are consistent with a modulation of the received radar power due to the birefringence of polar ice, and therefore indicate the presence of bulk fabric anisotropy. Here, we investigate the periodic component of birefringence-induced radar power recorded in airborne radar data at the eastern shear margin of Thwaites Glacier and quantify the lateral variation in azimuthal fabric strength across this margin. We find the depth variability of birefringence periodicity crossing the shear margin to be a visual expression of its shear state and its development, which appears consistent with present-day ice deformation. The morphology of the birefringent patterns is centered at the location of maximum shear and observed in all cross-margin profiles, consistent with predictions of ice fabric when subjected to simple shear. The englacial fabric appears stronger inside the ice stream than outward of the shear margin. The detection of birefringent periodicity from non-polarimetric radargrams presents a novel use of subsurface radar to ... |
author2 |
University of St Andrews. School of Geography & Sustainable Development |
format |
Article in Journal/Newspaper |
author |
Young, T. J. Schroeder, D. M. Jordan, T. M. Christoffersen, P. Tulaczyk, S. M. Culberg, R. Bienert, N. L. |
author_facet |
Young, T. J. Schroeder, D. M. Jordan, T. M. Christoffersen, P. Tulaczyk, S. M. Culberg, R. Bienert, N. L. |
author_sort |
Young, T. J. |
title |
Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica |
title_short |
Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica |
title_full |
Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica |
title_fullStr |
Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica |
title_full_unstemmed |
Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica |
title_sort |
inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of thwaites glacier, west antarctica |
publishDate |
2023 |
url |
http://hdl.handle.net/10023/27405 https://doi.org/10.1029/2020jf006023 |
long_lat |
ENVELOPE(-45.050,-45.050,-60.733,-60.733) ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Antarctic Christoffersen Thwaites Glacier West Antarctica |
geographic_facet |
Antarctic Christoffersen Thwaites Glacier West Antarctica |
genre |
Antarc* Antarctic Antarctica Antarctica Journal British Antarctic Survey Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Antarctica Journal British Antarctic Survey Thwaites Glacier West Antarctica |
op_relation |
Journal of Geophysical Research: Earth Surface Young , T J , Schroeder , D M , Jordan , T M , Christoffersen , P , Tulaczyk , S M , Culberg , R & Bienert , N L 2021 , ' Inferring ice fabric from birefringence loss in airborne radargrams : application to the eastern shear margin of Thwaites Glacier, West Antarctica ' , Journal of Geophysical Research: Earth Surface , vol. 126 , no. 5 . https://doi.org/10.1029/2020jf006023 2169-9011 PURE: 284141722 PURE UUID: 5e655a40-3ba1-4a56-9240-86dcd734ef4b Bibtex: Young_2021 ORCID: /0000-0001-5865-3459/work/133734041 http://hdl.handle.net/10023/27405 https://doi.org/10.1029/2020jf006023 |
op_rights |
Copyright © 2021. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
op_doi |
https://doi.org/10.1029/2020jf006023 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
126 |
container_issue |
5 |
_version_ |
1770274827207180288 |