The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream
Isolated areas of high basal drag, or ‘sticky spots’, are important and poorly understood features in the force balance and dynamics of West Antarctic ice streams. Characterizing sticky spots formed by thin or drying subglacial till using ice-penetrating radar is theoretically possible, as high rada...
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International Glaciological Society
2014
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Online Access: | http://nora.nerc.ac.uk/id/eprint/507214/ https://nora.nerc.ac.uk/id/eprint/507214/1/t67A052.pdf https://doi.org/10.3189/2014AoG67A052 |
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ftnerc:oai:nora.nerc.ac.uk:507214 2023-05-15T13:29:45+02:00 The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream Ashmore, David W. Bingham, Robert G. Hindmarsh, Richard C.A. Corr, Hugh F.J. Joughin, Ian R. 2014-04 text http://nora.nerc.ac.uk/id/eprint/507214/ https://nora.nerc.ac.uk/id/eprint/507214/1/t67A052.pdf https://doi.org/10.3189/2014AoG67A052 en eng International Glaciological Society https://nora.nerc.ac.uk/id/eprint/507214/1/t67A052.pdf Ashmore, David W.; Bingham, Robert G.; Hindmarsh, Richard C.A. orcid:0000-0003-1633-2416 Corr, Hugh F.J.; Joughin, Ian R. 2014 The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream. Annals of Glaciology, 55 (67). 29-38. https://doi.org/10.3189/2014AoG67A052 <https://doi.org/10.3189/2014AoG67A052> cc_by CC-BY Publication - Article PeerReviewed 2014 ftnerc https://doi.org/10.3189/2014AoG67A052 2023-02-04T19:39:38Z Isolated areas of high basal drag, or ‘sticky spots’, are important and poorly understood features in the force balance and dynamics of West Antarctic ice streams. Characterizing sticky spots formed by thin or drying subglacial till using ice-penetrating radar is theoretically possible, as high radar bed-returned power (BRP) is commonly related to an abundance of free water at the ice/bed interface, provided losses from englacial attenuation can be estimated. In this study we use airborne radar data collected over Evans Ice Stream to extract BRP profiles and test the sensitivity of BRP to the adopted englacial attenuation correction. We analyse 11 �20km profiles in four fast-flow areas where sticky spots have been inferred to exist on the basis of model and surface data inversions. In the majority of profiles we note that the increase in basal drag is accompanied by a decrease in BRP and suggest that this is evidence both for the presence of a sticky spot in those locations and that local variations in subglacial hydrology are responsible for their existence. A comparison is made between empirical and numerical modelling approaches for deriving englacial attenuation, and our findings generally support previous studies that advocate a modelling approach. Article in Journal/Newspaper Annals of Glaciology Antarc* Antarctic Evans Ice Stream Natural Environment Research Council: NERC Open Research Archive Antarctic Evans Ice Stream ENVELOPE(-78.000,-78.000,-76.000,-76.000) Annals of Glaciology 55 67 29 38 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Isolated areas of high basal drag, or ‘sticky spots’, are important and poorly understood features in the force balance and dynamics of West Antarctic ice streams. Characterizing sticky spots formed by thin or drying subglacial till using ice-penetrating radar is theoretically possible, as high radar bed-returned power (BRP) is commonly related to an abundance of free water at the ice/bed interface, provided losses from englacial attenuation can be estimated. In this study we use airborne radar data collected over Evans Ice Stream to extract BRP profiles and test the sensitivity of BRP to the adopted englacial attenuation correction. We analyse 11 �20km profiles in four fast-flow areas where sticky spots have been inferred to exist on the basis of model and surface data inversions. In the majority of profiles we note that the increase in basal drag is accompanied by a decrease in BRP and suggest that this is evidence both for the presence of a sticky spot in those locations and that local variations in subglacial hydrology are responsible for their existence. A comparison is made between empirical and numerical modelling approaches for deriving englacial attenuation, and our findings generally support previous studies that advocate a modelling approach. |
format |
Article in Journal/Newspaper |
author |
Ashmore, David W. Bingham, Robert G. Hindmarsh, Richard C.A. Corr, Hugh F.J. Joughin, Ian R. |
spellingShingle |
Ashmore, David W. Bingham, Robert G. Hindmarsh, Richard C.A. Corr, Hugh F.J. Joughin, Ian R. The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream |
author_facet |
Ashmore, David W. Bingham, Robert G. Hindmarsh, Richard C.A. Corr, Hugh F.J. Joughin, Ian R. |
author_sort |
Ashmore, David W. |
title |
The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream |
title_short |
The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream |
title_full |
The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream |
title_fullStr |
The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream |
title_full_unstemmed |
The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream |
title_sort |
relationship between sticky spots and radar reflectivity beneath an active west antarctic ice stream |
publisher |
International Glaciological Society |
publishDate |
2014 |
url |
http://nora.nerc.ac.uk/id/eprint/507214/ https://nora.nerc.ac.uk/id/eprint/507214/1/t67A052.pdf https://doi.org/10.3189/2014AoG67A052 |
long_lat |
ENVELOPE(-78.000,-78.000,-76.000,-76.000) |
geographic |
Antarctic Evans Ice Stream |
geographic_facet |
Antarctic Evans Ice Stream |
genre |
Annals of Glaciology Antarc* Antarctic Evans Ice Stream |
genre_facet |
Annals of Glaciology Antarc* Antarctic Evans Ice Stream |
op_relation |
https://nora.nerc.ac.uk/id/eprint/507214/1/t67A052.pdf Ashmore, David W.; Bingham, Robert G.; Hindmarsh, Richard C.A. orcid:0000-0003-1633-2416 Corr, Hugh F.J.; Joughin, Ian R. 2014 The relationship between sticky spots and radar reflectivity beneath an active West Antarctic ice stream. Annals of Glaciology, 55 (67). 29-38. https://doi.org/10.3189/2014AoG67A052 <https://doi.org/10.3189/2014AoG67A052> |
op_rights |
cc_by |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.3189/2014AoG67A052 |
container_title |
Annals of Glaciology |
container_volume |
55 |
container_issue |
67 |
container_start_page |
29 |
op_container_end_page |
38 |
_version_ |
1766002655256117248 |