Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides
Ice flow in divide areas is strongly anisotropic. The evolution of ice fabric, from the onset of divide flow towards steady state with a fully developed fabric, has been shown to profoundly affect both the stratigraphy and surface topography of ice divides. Here, we investigate the effects of ice fl...
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Copernicus Publications
2012
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ftnerc:oai:nora.nerc.ac.uk:18411 2023-05-15T16:39:10+02:00 Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides Martin, Carlos Gudmundsson, G. Hilmar 2012 text http://nora.nerc.ac.uk/id/eprint/18411/ https://nora.nerc.ac.uk/id/eprint/18411/1/tc-6-1221-2012.pdf http://www.the-cryosphere.net/6/1221/2012/tc-6-1221-2012.html en eng Copernicus Publications https://nora.nerc.ac.uk/id/eprint/18411/1/tc-6-1221-2012.pdf Martin, Carlos orcid:0000-0002-2661-169X Gudmundsson, G. Hilmar orcid:0000-0003-4236-5369 . 2012 Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides. The Cryosphere, 6 (5). 1221-1229. https://doi.org/10.5194/tc-6-1221-2012 <https://doi.org/10.5194/tc-6-1221-2012> Publication - Article PeerReviewed 2012 ftnerc https://doi.org/10.5194/tc-6-1221-2012 2023-02-04T19:31:42Z Ice flow in divide areas is strongly anisotropic. The evolution of ice fabric, from the onset of divide flow towards steady state with a fully developed fabric, has been shown to profoundly affect both the stratigraphy and surface topography of ice divides. Here, we investigate the effects of ice flow on the age-versus-depth relationship at ice divides by using a full Stokes thermomechanical model with a non-linear anisotropic constitutive relation between stress and strain rates. We compare our results with analytical approximations commonly employed in age–depth predictions, such as the Dansgaard and Lliboutry approximations. We show that these approximations systematically underestimate the age of ice at fully developed divides by as much as one order of magnitude. We also show that divides with fully developed fabric are ideal locations for ice-core extraction because ice under them can be up to one order of magnitude older than ice at the same depth at the flanks. In addition, these divides have a distinctive morphological structure that allows them to be clearly identified from satellite imagery or ground-penetrating radar data. Article in Journal/Newspaper ice core The Cryosphere Natural Environment Research Council: NERC Open Research Archive The Cryosphere 6 5 1221 1229 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Ice flow in divide areas is strongly anisotropic. The evolution of ice fabric, from the onset of divide flow towards steady state with a fully developed fabric, has been shown to profoundly affect both the stratigraphy and surface topography of ice divides. Here, we investigate the effects of ice flow on the age-versus-depth relationship at ice divides by using a full Stokes thermomechanical model with a non-linear anisotropic constitutive relation between stress and strain rates. We compare our results with analytical approximations commonly employed in age–depth predictions, such as the Dansgaard and Lliboutry approximations. We show that these approximations systematically underestimate the age of ice at fully developed divides by as much as one order of magnitude. We also show that divides with fully developed fabric are ideal locations for ice-core extraction because ice under them can be up to one order of magnitude older than ice at the same depth at the flanks. In addition, these divides have a distinctive morphological structure that allows them to be clearly identified from satellite imagery or ground-penetrating radar data. |
format |
Article in Journal/Newspaper |
author |
Martin, Carlos Gudmundsson, G. Hilmar |
spellingShingle |
Martin, Carlos Gudmundsson, G. Hilmar Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides |
author_facet |
Martin, Carlos Gudmundsson, G. Hilmar |
author_sort |
Martin, Carlos |
title |
Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides |
title_short |
Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides |
title_full |
Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides |
title_fullStr |
Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides |
title_full_unstemmed |
Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides |
title_sort |
effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
http://nora.nerc.ac.uk/id/eprint/18411/ https://nora.nerc.ac.uk/id/eprint/18411/1/tc-6-1221-2012.pdf http://www.the-cryosphere.net/6/1221/2012/tc-6-1221-2012.html |
genre |
ice core The Cryosphere |
genre_facet |
ice core The Cryosphere |
op_relation |
https://nora.nerc.ac.uk/id/eprint/18411/1/tc-6-1221-2012.pdf Martin, Carlos orcid:0000-0002-2661-169X Gudmundsson, G. Hilmar orcid:0000-0003-4236-5369 . 2012 Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides. The Cryosphere, 6 (5). 1221-1229. https://doi.org/10.5194/tc-6-1221-2012 <https://doi.org/10.5194/tc-6-1221-2012> |
op_doi |
https://doi.org/10.5194/tc-6-1221-2012 |
container_title |
The Cryosphere |
container_volume |
6 |
container_issue |
5 |
container_start_page |
1221 |
op_container_end_page |
1229 |
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1766029499379482624 |