Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica
Basal properties beneath ice streams and glaciers are known to be a control for ice flow dynamics, hence knowledge of them is crucial for predicting sea level due to changes in glacial dynamics. Basal properties, processes and topography also drive the formation of subglacial landforms. Bed properti...
Published in: | Journal of Geophysical Research: Earth Surface |
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American Geophysical Union
2022
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Online Access: | http://nora.nerc.ac.uk/id/eprint/529402/ https://nora.nerc.ac.uk/id/eprint/529402/1/JGR%20Earth%20Surface%20-%202021%20-%20Schlegel%20-%20Radar%20Derived%20Subglacial%20Properties%20and%20Landforms%20Beneath%20Rutford%20Ice%20Stream%20West.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JF006349 |
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ftnerc:oai:nora.nerc.ac.uk:529402 2023-05-15T13:41:45+02:00 Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica Schlegel, Rebecca Murray, Tavi Smith, Andrew M. Brisbourne, Alex M. Booth, Adam D. King, Edward C. Clark, Roger A. 2022-01-07 text http://nora.nerc.ac.uk/id/eprint/529402/ https://nora.nerc.ac.uk/id/eprint/529402/1/JGR%20Earth%20Surface%20-%202021%20-%20Schlegel%20-%20Radar%20Derived%20Subglacial%20Properties%20and%20Landforms%20Beneath%20Rutford%20Ice%20Stream%20West.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JF006349 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/529402/1/JGR%20Earth%20Surface%20-%202021%20-%20Schlegel%20-%20Radar%20Derived%20Subglacial%20Properties%20and%20Landforms%20Beneath%20Rutford%20Ice%20Stream%20West.pdf Schlegel, Rebecca; Murray, Tavi; Smith, Andrew M. orcid:0000-0001-8577-482X Brisbourne, Alex M. orcid:0000-0002-9887-7120 Booth, Adam D.; King, Edward C. orcid:0000-0003-3793-3915 Clark, Roger A. 2022 Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica. Journal of Geophysical Research: Earth Surface, 127 (1), e2021JF006349. 18, pp. https://doi.org/10.1029/2021JF006349 <https://doi.org/10.1029/2021JF006349> cc_by_4 CC-BY Publication - Article PeerReviewed 2022 ftnerc https://doi.org/10.1029/2021JF006349 2023-02-04T19:51:38Z Basal properties beneath ice streams and glaciers are known to be a control for ice flow dynamics, hence knowledge of them is crucial for predicting sea level due to changes in glacial dynamics. Basal properties, processes and topography also drive the formation of subglacial landforms. Bed properties beneath Rutford Ice Stream (West Antarctica) have previously been described using seismic acoustic impedance measurements at a sparse spatial coverage. Here, we derive bed properties in a 15 x 17 km grid of surface radar data with coverage and sampling much higher than previous seismic studies. Bed reflection amplitudes in surface radar data were calibrated using sediment porosities (ranging from 0.4 – 0.5) derived from seismic acoustic impedance. We find the bed properties are spatially variable, consisting of low porosity material in some areas and soft sediment in other areas. Comparison of seismic and surface radar data imply the low porosity material to be a consolidated sediment or sedimentary rock. Mega-scale glacial lineations (MSGLs) are ubiquitous on the bed and consist of soft, high porosity, probably deforming sediment, consistent with previous interpretations of MSGLs. We find some MSGLs have high reflectivity on their crest, interpreted as water bodies overlying high porosity sediment, whereas the trough around and the upstream end of some landforms consist of low porosity material. Integrating these different observations, we place constraints on possible explanations for the occurrence of water on the crest of landforms. Article in Journal/Newspaper Antarc* Antarctica Antarctica Journal Rutford Ice Stream West Antarctica Natural Environment Research Council: NERC Open Research Archive West Antarctica Rutford ENVELOPE(-85.300,-85.300,-78.600,-78.600) Rutford Ice Stream ENVELOPE(-80.000,-80.000,-79.167,-79.167) Journal of Geophysical Research: Earth Surface 127 1 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Basal properties beneath ice streams and glaciers are known to be a control for ice flow dynamics, hence knowledge of them is crucial for predicting sea level due to changes in glacial dynamics. Basal properties, processes and topography also drive the formation of subglacial landforms. Bed properties beneath Rutford Ice Stream (West Antarctica) have previously been described using seismic acoustic impedance measurements at a sparse spatial coverage. Here, we derive bed properties in a 15 x 17 km grid of surface radar data with coverage and sampling much higher than previous seismic studies. Bed reflection amplitudes in surface radar data were calibrated using sediment porosities (ranging from 0.4 – 0.5) derived from seismic acoustic impedance. We find the bed properties are spatially variable, consisting of low porosity material in some areas and soft sediment in other areas. Comparison of seismic and surface radar data imply the low porosity material to be a consolidated sediment or sedimentary rock. Mega-scale glacial lineations (MSGLs) are ubiquitous on the bed and consist of soft, high porosity, probably deforming sediment, consistent with previous interpretations of MSGLs. We find some MSGLs have high reflectivity on their crest, interpreted as water bodies overlying high porosity sediment, whereas the trough around and the upstream end of some landforms consist of low porosity material. Integrating these different observations, we place constraints on possible explanations for the occurrence of water on the crest of landforms. |
format |
Article in Journal/Newspaper |
author |
Schlegel, Rebecca Murray, Tavi Smith, Andrew M. Brisbourne, Alex M. Booth, Adam D. King, Edward C. Clark, Roger A. |
spellingShingle |
Schlegel, Rebecca Murray, Tavi Smith, Andrew M. Brisbourne, Alex M. Booth, Adam D. King, Edward C. Clark, Roger A. Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica |
author_facet |
Schlegel, Rebecca Murray, Tavi Smith, Andrew M. Brisbourne, Alex M. Booth, Adam D. King, Edward C. Clark, Roger A. |
author_sort |
Schlegel, Rebecca |
title |
Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica |
title_short |
Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica |
title_full |
Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica |
title_fullStr |
Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica |
title_full_unstemmed |
Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica |
title_sort |
radar derived subglacial properties and landforms beneath rutford ice stream, west antarctica |
publisher |
American Geophysical Union |
publishDate |
2022 |
url |
http://nora.nerc.ac.uk/id/eprint/529402/ https://nora.nerc.ac.uk/id/eprint/529402/1/JGR%20Earth%20Surface%20-%202021%20-%20Schlegel%20-%20Radar%20Derived%20Subglacial%20Properties%20and%20Landforms%20Beneath%20Rutford%20Ice%20Stream%20West.pdf https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021JF006349 |
long_lat |
ENVELOPE(-85.300,-85.300,-78.600,-78.600) ENVELOPE(-80.000,-80.000,-79.167,-79.167) |
geographic |
West Antarctica Rutford Rutford Ice Stream |
geographic_facet |
West Antarctica Rutford Rutford Ice Stream |
genre |
Antarc* Antarctica Antarctica Journal Rutford Ice Stream West Antarctica |
genre_facet |
Antarc* Antarctica Antarctica Journal Rutford Ice Stream West Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/529402/1/JGR%20Earth%20Surface%20-%202021%20-%20Schlegel%20-%20Radar%20Derived%20Subglacial%20Properties%20and%20Landforms%20Beneath%20Rutford%20Ice%20Stream%20West.pdf Schlegel, Rebecca; Murray, Tavi; Smith, Andrew M. orcid:0000-0001-8577-482X Brisbourne, Alex M. orcid:0000-0002-9887-7120 Booth, Adam D.; King, Edward C. orcid:0000-0003-3793-3915 Clark, Roger A. 2022 Radar derived subglacial properties and landforms beneath Rutford Ice Stream, West Antarctica. Journal of Geophysical Research: Earth Surface, 127 (1), e2021JF006349. 18, pp. https://doi.org/10.1029/2021JF006349 <https://doi.org/10.1029/2021JF006349> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2021JF006349 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
127 |
container_issue |
1 |
_version_ |
1766157224800944128 |