In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar
The Glen exponent ncharacterizes the stress-dependence of ice deformation, directly influencing the rate at which ice masses respond to external forcing. The slow deformation in large ice-sheets makes laboratory rheometry at representative strain-rates difficult. We develop a new technique to estima...
Published in: | Geophysical Research Letters |
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Format: | Article in Journal/Newspaper |
Language: | English |
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American Geophysical Union
2011
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Online Access: | http://nora.nerc.ac.uk/id/eprint/16519/ https://nora.nerc.ac.uk/id/eprint/16519/1/grl28735.pdf http://www.agu.org/journals/gl/gl1124/2011GL049843/2011GL049843.pdf |
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ftnerc:oai:nora.nerc.ac.uk:16519 2023-05-15T16:27:26+02:00 In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar Gillet-Chaulet, Fabien Hindmarsh, Richard C.A. Corr, Hugh F.J. King, Edward C. Jenkins, Adrian 2011 text http://nora.nerc.ac.uk/id/eprint/16519/ https://nora.nerc.ac.uk/id/eprint/16519/1/grl28735.pdf http://www.agu.org/journals/gl/gl1124/2011GL049843/2011GL049843.pdf en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/16519/1/grl28735.pdf Gillet-Chaulet, Fabien; Hindmarsh, Richard C.A. orcid:0000-0003-1633-2416 Corr, Hugh F.J.; King, Edward C. orcid:0000-0003-3793-3915 Jenkins, Adrian orcid:0000-0002-9117-0616 . 2011 In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar. Geophysical Research Letters, 38 (24), L24503. 6, pp. https://doi.org/10.1029/2011GL049843 <https://doi.org/10.1029/2011GL049843> Publication - Article PeerReviewed 2011 ftnerc https://doi.org/10.1029/2011GL049843 2023-02-04T19:30:35Z The Glen exponent ncharacterizes the stress-dependence of ice deformation, directly influencing the rate at which ice masses respond to external forcing. The slow deformation in large ice-sheets makes laboratory rheometry at representative strain-rates difficult. We develop a new technique to estimaten in-situ, deploying a phase-sensitive radar to measure vertical strain rates of around 10−4 yr−1within the top 1000 m of ice across ice divides at Summit and NEEM, Greenland. A fluid-dynamical feature, the Raymond Effect, predicts strong vertical strain-rate variation across divides over distances of a few ice-thicknesses. We achieve sufficient resolution to show this pattern, enabling us to estimaten= 4.5 by inverting our observations with flow modelling. This is higher than values previously used but consistent with other indirect measurements, implying laboratory measurements do not explore the full range of ice rheology and the consequent possibility of a greater sensitivity and responsiveness in ice-sheet dynamics. Article in Journal/Newspaper Greenland Ice Sheet Natural Environment Research Council: NERC Open Research Archive Greenland Geophysical Research Letters 38 24 n/a n/a |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
The Glen exponent ncharacterizes the stress-dependence of ice deformation, directly influencing the rate at which ice masses respond to external forcing. The slow deformation in large ice-sheets makes laboratory rheometry at representative strain-rates difficult. We develop a new technique to estimaten in-situ, deploying a phase-sensitive radar to measure vertical strain rates of around 10−4 yr−1within the top 1000 m of ice across ice divides at Summit and NEEM, Greenland. A fluid-dynamical feature, the Raymond Effect, predicts strong vertical strain-rate variation across divides over distances of a few ice-thicknesses. We achieve sufficient resolution to show this pattern, enabling us to estimaten= 4.5 by inverting our observations with flow modelling. This is higher than values previously used but consistent with other indirect measurements, implying laboratory measurements do not explore the full range of ice rheology and the consequent possibility of a greater sensitivity and responsiveness in ice-sheet dynamics. |
format |
Article in Journal/Newspaper |
author |
Gillet-Chaulet, Fabien Hindmarsh, Richard C.A. Corr, Hugh F.J. King, Edward C. Jenkins, Adrian |
spellingShingle |
Gillet-Chaulet, Fabien Hindmarsh, Richard C.A. Corr, Hugh F.J. King, Edward C. Jenkins, Adrian In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar |
author_facet |
Gillet-Chaulet, Fabien Hindmarsh, Richard C.A. Corr, Hugh F.J. King, Edward C. Jenkins, Adrian |
author_sort |
Gillet-Chaulet, Fabien |
title |
In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar |
title_short |
In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar |
title_full |
In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar |
title_fullStr |
In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar |
title_full_unstemmed |
In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar |
title_sort |
in-situ quantification of ice rheology and direct measurement of the raymond effect at summit, greenland using a phase-sensitive radar |
publisher |
American Geophysical Union |
publishDate |
2011 |
url |
http://nora.nerc.ac.uk/id/eprint/16519/ https://nora.nerc.ac.uk/id/eprint/16519/1/grl28735.pdf http://www.agu.org/journals/gl/gl1124/2011GL049843/2011GL049843.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_relation |
https://nora.nerc.ac.uk/id/eprint/16519/1/grl28735.pdf Gillet-Chaulet, Fabien; Hindmarsh, Richard C.A. orcid:0000-0003-1633-2416 Corr, Hugh F.J.; King, Edward C. orcid:0000-0003-3793-3915 Jenkins, Adrian orcid:0000-0002-9117-0616 . 2011 In-situ quantification of ice rheology and direct measurement of the Raymond Effect at Summit, Greenland using a phase-sensitive radar. Geophysical Research Letters, 38 (24), L24503. 6, pp. https://doi.org/10.1029/2011GL049843 <https://doi.org/10.1029/2011GL049843> |
op_doi |
https://doi.org/10.1029/2011GL049843 |
container_title |
Geophysical Research Letters |
container_volume |
38 |
container_issue |
24 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1766016608127418368 |