Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps
Crystal orientation fabric (COF) analysis provides information about the c -axis orientation of ice grains and the associated anisotropy and microstructural information about deformation and recrystallisation processes within the glacier. This information can be used to introduce modules that fully...
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ftdoajarticles:oai:doaj.org/article:9a31dfd48dc54ec6943c515b0ac80ea3 2023-05-15T16:39:20+02:00 Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps S. Hellmann J. Kerch I. Weikusat A. Bauder M. Grab G. Jouvet M. Schwikowski H. Maurer 2021-02-01T00:00:00Z https://doi.org/10.5194/tc-15-677-2021 https://doaj.org/article/9a31dfd48dc54ec6943c515b0ac80ea3 EN eng Copernicus Publications https://tc.copernicus.org/articles/15/677/2021/tc-15-677-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-677-2021 1994-0416 1994-0424 https://doaj.org/article/9a31dfd48dc54ec6943c515b0ac80ea3 The Cryosphere, Vol 15, Pp 677-694 (2021) Environmental sciences GE1-350 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/tc-15-677-2021 2022-12-30T22:02:41Z Crystal orientation fabric (COF) analysis provides information about the c -axis orientation of ice grains and the associated anisotropy and microstructural information about deformation and recrystallisation processes within the glacier. This information can be used to introduce modules that fully describe the microstructural anisotropy or at least direction-dependent enhancement factors for glacier modelling. The COF was studied at an ice core that was obtained from the temperate Rhonegletscher, located in the central Swiss Alps. Seven samples, extracted at depths between 2 and 79 m, were analysed with an automatic fabric analyser. The COF analysis revealed conspicuous four-maxima patterns of the c -axis orientations at all depths. Additional data, such as microstructural images, produced during the ice sample preparation process, were considered to interpret these patterns. Furthermore, repeated high-precision global navigation satellite system (GNSS) surveying allowed the local glacier flow direction to be determined. The relative movements of the individual surveying points indicated longitudinal compressive stresses parallel to the glacier flow. Finally, numerical modelling of the ice flow permitted estimation of the local stress distribution. An integrated analysis of all the data sets provided indications and suggestions for the development of the four-maxima patterns. The centroid of the four-maxima patterns of the individual core samples and the coinciding maximum eigenvector approximately align with the compressive stress directions obtained from numerical modelling with an exception for the deepest sample. The clustering of the c axes in four maxima surrounding the predominant compressive stress direction is most likely the result of a fast migration recrystallisation. This interpretation is supported by air bubble analysis of large-area scanning macroscope (LASM) images. Our results indicate that COF studies, which have so far predominantly been performed on cold ice samples from the polar regions, ... Article in Journal/Newspaper ice core The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 15 2 677 694 |
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Directory of Open Access Journals: DOAJ Articles |
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topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
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Environmental sciences GE1-350 Geology QE1-996.5 S. Hellmann J. Kerch I. Weikusat A. Bauder M. Grab G. Jouvet M. Schwikowski H. Maurer Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Crystal orientation fabric (COF) analysis provides information about the c -axis orientation of ice grains and the associated anisotropy and microstructural information about deformation and recrystallisation processes within the glacier. This information can be used to introduce modules that fully describe the microstructural anisotropy or at least direction-dependent enhancement factors for glacier modelling. The COF was studied at an ice core that was obtained from the temperate Rhonegletscher, located in the central Swiss Alps. Seven samples, extracted at depths between 2 and 79 m, were analysed with an automatic fabric analyser. The COF analysis revealed conspicuous four-maxima patterns of the c -axis orientations at all depths. Additional data, such as microstructural images, produced during the ice sample preparation process, were considered to interpret these patterns. Furthermore, repeated high-precision global navigation satellite system (GNSS) surveying allowed the local glacier flow direction to be determined. The relative movements of the individual surveying points indicated longitudinal compressive stresses parallel to the glacier flow. Finally, numerical modelling of the ice flow permitted estimation of the local stress distribution. An integrated analysis of all the data sets provided indications and suggestions for the development of the four-maxima patterns. The centroid of the four-maxima patterns of the individual core samples and the coinciding maximum eigenvector approximately align with the compressive stress directions obtained from numerical modelling with an exception for the deepest sample. The clustering of the c axes in four maxima surrounding the predominant compressive stress direction is most likely the result of a fast migration recrystallisation. This interpretation is supported by air bubble analysis of large-area scanning macroscope (LASM) images. Our results indicate that COF studies, which have so far predominantly been performed on cold ice samples from the polar regions, ... |
format |
Article in Journal/Newspaper |
author |
S. Hellmann J. Kerch I. Weikusat A. Bauder M. Grab G. Jouvet M. Schwikowski H. Maurer |
author_facet |
S. Hellmann J. Kerch I. Weikusat A. Bauder M. Grab G. Jouvet M. Schwikowski H. Maurer |
author_sort |
S. Hellmann |
title |
Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps |
title_short |
Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps |
title_full |
Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps |
title_fullStr |
Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps |
title_full_unstemmed |
Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps |
title_sort |
crystallographic analysis of temperate ice on rhonegletscher, swiss alps |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-677-2021 https://doaj.org/article/9a31dfd48dc54ec6943c515b0ac80ea3 |
genre |
ice core The Cryosphere |
genre_facet |
ice core The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 677-694 (2021) |
op_relation |
https://tc.copernicus.org/articles/15/677/2021/tc-15-677-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-677-2021 1994-0416 1994-0424 https://doaj.org/article/9a31dfd48dc54ec6943c515b0ac80ea3 |
op_doi |
https://doi.org/10.5194/tc-15-677-2021 |
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The Cryosphere |
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15 |
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677 |
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694 |
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