Laterally varying basal conditions beneath ice Streams B and C, West Antarctica
Abstract The study of the phase of reflections of Ρ waves off the base of Ice Streams Β and C, and Ridge BC, indicates that acoustic impedances of the beds of both ice streams vary laterally. In some places, the impedance is higher than in the ice (a high-impedance bed) and in some places it is less...
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Language: | English |
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Cambridge University Press (CUP)
1993
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Online Access: | http://dx.doi.org/10.1017/s0022143000016403 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000016403 |
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crcambridgeupr:10.1017/s0022143000016403 2024-03-03T08:37:15+00:00 Laterally varying basal conditions beneath ice Streams B and C, West Antarctica Atre, Shashank R. Bentley, Charles R. 1993 http://dx.doi.org/10.1017/s0022143000016403 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000016403 en eng Cambridge University Press (CUP) Journal of Glaciology volume 39, issue 133, page 507-514 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1993 crcambridgeupr https://doi.org/10.1017/s0022143000016403 2024-02-08T08:34:04Z Abstract The study of the phase of reflections of Ρ waves off the base of Ice Streams Β and C, and Ridge BC, indicates that acoustic impedances of the beds of both ice streams vary laterally. In some places, the impedance is higher than in the ice (a high-impedance bed) and in some places it is less (a low-impedance bed). The estimated impedances in a dilated bed (porosity 0.4) and in a model of the lowermost ice that takes into account the relatively low P-wave speed in ice at or very near the melting point are nearly the same. Whether the impedance in the bed is greater or less than in the ice could depend on minor changes in the nature of the sediments composing the bed, or the physical state of the bed (e.g. porosity) that could occur laterally. Lateral variations of this kind provide a ready explanation for the observations on Ice Stream B. The bed under a substantial part of Ice Stream C that exhibits a low-impedance bed also must be dilated. The evaluation of the state of the bed under the rest of Ice Stream C and on Ridge BC requires further analysis, which is in progress. Article in Journal/Newspaper Antarc* Antarctica Ice Stream B Ice Stream C Journal of Glaciology West Antarctica Cambridge University Press West Antarctica Journal of Glaciology 39 133 507 514 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Atre, Shashank R. Bentley, Charles R. Laterally varying basal conditions beneath ice Streams B and C, West Antarctica |
topic_facet |
Earth-Surface Processes |
description |
Abstract The study of the phase of reflections of Ρ waves off the base of Ice Streams Β and C, and Ridge BC, indicates that acoustic impedances of the beds of both ice streams vary laterally. In some places, the impedance is higher than in the ice (a high-impedance bed) and in some places it is less (a low-impedance bed). The estimated impedances in a dilated bed (porosity 0.4) and in a model of the lowermost ice that takes into account the relatively low P-wave speed in ice at or very near the melting point are nearly the same. Whether the impedance in the bed is greater or less than in the ice could depend on minor changes in the nature of the sediments composing the bed, or the physical state of the bed (e.g. porosity) that could occur laterally. Lateral variations of this kind provide a ready explanation for the observations on Ice Stream B. The bed under a substantial part of Ice Stream C that exhibits a low-impedance bed also must be dilated. The evaluation of the state of the bed under the rest of Ice Stream C and on Ridge BC requires further analysis, which is in progress. |
format |
Article in Journal/Newspaper |
author |
Atre, Shashank R. Bentley, Charles R. |
author_facet |
Atre, Shashank R. Bentley, Charles R. |
author_sort |
Atre, Shashank R. |
title |
Laterally varying basal conditions beneath ice Streams B and C, West Antarctica |
title_short |
Laterally varying basal conditions beneath ice Streams B and C, West Antarctica |
title_full |
Laterally varying basal conditions beneath ice Streams B and C, West Antarctica |
title_fullStr |
Laterally varying basal conditions beneath ice Streams B and C, West Antarctica |
title_full_unstemmed |
Laterally varying basal conditions beneath ice Streams B and C, West Antarctica |
title_sort |
laterally varying basal conditions beneath ice streams b and c, west antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
1993 |
url |
http://dx.doi.org/10.1017/s0022143000016403 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000016403 |
geographic |
West Antarctica |
geographic_facet |
West Antarctica |
genre |
Antarc* Antarctica Ice Stream B Ice Stream C Journal of Glaciology West Antarctica |
genre_facet |
Antarc* Antarctica Ice Stream B Ice Stream C Journal of Glaciology West Antarctica |
op_source |
Journal of Glaciology volume 39, issue 133, page 507-514 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000016403 |
container_title |
Journal of Glaciology |
container_volume |
39 |
container_issue |
133 |
container_start_page |
507 |
op_container_end_page |
514 |
_version_ |
1792497824840024064 |