Inferring Ice Fabric From Birefringence Loss in Airborne Radargrams: Application to the Eastern Shear Margin of Thwaites Glacier, West Antarctica
<jats:title>Abstract</jats:title><jats:p>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 pre...
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ftunivcam:oai:www.repository.cam.ac.uk:1810/321755 2024-01-14T10:01:38+01:00 Inferring Ice Fabric From Birefringence Loss in Airborne Radargrams: Application to the Eastern Shear Margin of Thwaites Glacier, West Antarctica Young, TJ Schroeder, DM Jordan, TM Christoffersen, P Tulaczyk, SM Culberg, R Bienert, NL 2021 application/pdf https://www.repository.cam.ac.uk/handle/1810/321755 https://doi.org/10.17863/CAM.68878 eng eng American Geophysical Union (AGU) http://dx.doi.org/10.1029/2020jf006023 Journal of Geophysical Research: Earth Surface https://www.repository.cam.ac.uk/handle/1810/321755 doi:10.17863/CAM.68878 All rights reserved Antarctica birefringence fabric glaciology ice penetrating radar polarimetry Article 2021 ftunivcam https://doi.org/10.17863/CAM.68878 2023-12-21T23:21:09Z <jats:title>Abstract</jats:title><jats:p>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 constrain lateral variations in fabric strength, locate present and past shear margins, and characterize the deformation history of polar ice sheets.</jats:p> National Science Foundation Article in Journal/Newspaper Antarc* Antarctica Thwaites Glacier West Antarctica Apollo - University of Cambridge Repository Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) West Antarctica |
institution |
Open Polar |
collection |
Apollo - University of Cambridge Repository |
op_collection_id |
ftunivcam |
language |
English |
topic |
Antarctica birefringence fabric glaciology ice penetrating radar polarimetry |
spellingShingle |
Antarctica birefringence fabric glaciology ice penetrating radar polarimetry Young, TJ Schroeder, DM Jordan, TM Christoffersen, P Tulaczyk, SM Culberg, R Bienert, NL Inferring Ice Fabric From Birefringence Loss in Airborne Radargrams: Application to the Eastern Shear Margin of Thwaites Glacier, West Antarctica |
topic_facet |
Antarctica birefringence fabric glaciology ice penetrating radar polarimetry |
description |
<jats:title>Abstract</jats:title><jats:p>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 constrain lateral variations in fabric strength, locate present and past shear margins, and characterize the deformation history of polar ice sheets.</jats:p> National Science Foundation |
format |
Article in Journal/Newspaper |
author |
Young, TJ Schroeder, DM Jordan, TM Christoffersen, P Tulaczyk, SM Culberg, R Bienert, NL |
author_facet |
Young, TJ Schroeder, DM Jordan, TM Christoffersen, P Tulaczyk, SM Culberg, R Bienert, NL |
author_sort |
Young, TJ |
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 |
publisher |
American Geophysical Union (AGU) |
publishDate |
2021 |
url |
https://www.repository.cam.ac.uk/handle/1810/321755 https://doi.org/10.17863/CAM.68878 |
long_lat |
ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Thwaites Glacier West Antarctica |
geographic_facet |
Thwaites Glacier West Antarctica |
genre |
Antarc* Antarctica Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctica Thwaites Glacier West Antarctica |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/321755 doi:10.17863/CAM.68878 |
op_rights |
All rights reserved |
op_doi |
https://doi.org/10.17863/CAM.68878 |
_version_ |
1788067395380707328 |