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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fttriple:oai:gotriple.eu:oai:doaj.org/article:3e01271105eb4f7d8b936570a799203d 2023-05-15T16:39:11+02:00 Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides C. Martín G. H. Gudmundsson 2012-10-01 https://doi.org/10.5194/tc-6-1221-2012 http://www.the-cryosphere.net/6/1221/2012/tc-6-1221-2012.pdf https://doaj.org/article/3e01271105eb4f7d8b936570a799203d en eng Copernicus Publications doi:10.5194/tc-6-1221-2012 1994-0416 1994-0424 http://www.the-cryosphere.net/6/1221/2012/tc-6-1221-2012.pdf https://doaj.org/article/3e01271105eb4f7d8b936570a799203d undefined The Cryosphere, Vol 6, Iss 5, Pp 1221-1229 (2012) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2012 fttriple https://doi.org/10.5194/tc-6-1221-2012 2023-01-22T16:34:58Z 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 Unknown The Cryosphere 6 5 1221 1229 |
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English |
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geo envir |
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geo envir C. Martín G. H. Gudmundsson Effects of nonlinear rheology, temperature and anisotropy on the relationship between age and depth at ice divides |
topic_facet |
geo envir |
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 |
C. Martín G. H. Gudmundsson |
author_facet |
C. Martín G. H. Gudmundsson |
author_sort |
C. Martín |
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 |
https://doi.org/10.5194/tc-6-1221-2012 http://www.the-cryosphere.net/6/1221/2012/tc-6-1221-2012.pdf https://doaj.org/article/3e01271105eb4f7d8b936570a799203d |
genre |
ice core The Cryosphere |
genre_facet |
ice core The Cryosphere |
op_source |
The Cryosphere, Vol 6, Iss 5, Pp 1221-1229 (2012) |
op_relation |
doi:10.5194/tc-6-1221-2012 1994-0416 1994-0424 http://www.the-cryosphere.net/6/1221/2012/tc-6-1221-2012.pdf https://doaj.org/article/3e01271105eb4f7d8b936570a799203d |
op_rights |
undefined |
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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1766029509554864128 |