Crystalline Texture of the 2083 m Ice Core at Vostok Station, Antarctica
Abstract Crystalline texture and c -axis orientation of the 2083 m ice core at Vostok Station, covering more than 150kyear, reveal the existence of strong anisotropics. Changes in crystal size with depth are compatible with the growth of grains driven by the free energy of grain boundaries. A smalle...
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Cambridge University Press (CUP)
1989
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crcambridgeupr:10.1017/s0022143000009321 2024-09-15T17:41:39+00:00 Crystalline Texture of the 2083 m Ice Core at Vostok Station, Antarctica Lipenkov, V.Ya. Barkov, N.I. Duval, P. Pimienta, P. 1989 http://dx.doi.org/10.1017/s0022143000009321 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000009321 en eng Cambridge University Press (CUP) Journal of Glaciology volume 35, issue 121, page 392-398 ISSN 0022-1430 1727-5652 journal-article 1989 crcambridgeupr https://doi.org/10.1017/s0022143000009321 2024-08-07T04:03:22Z Abstract Crystalline texture and c -axis orientation of the 2083 m ice core at Vostok Station, covering more than 150kyear, reveal the existence of strong anisotropics. Changes in crystal size with depth are compatible with the growth of grains driven by the free energy of grain boundaries. A smaller growth rate appears to be associated with cold periods. A gradual increase in the horizontal elongation of grains was observed between 350 and 680 m. But, the mean value of the coefficient of the linear dimensional orientation of grains does not change below 700 m. The c -axis orientation of ice grains tends to orientate perpendicular to the direction of the elongation of grains, forming a vertical girdle pattern. This characteristic fabric has been interpreted as resulting from the gradual rotation of grains by basal glide under uniaxial longitudinal tension. The rotation of grains was calculated with respect to the total strain, simulating the formation of the girdle fabric pattern. The fabric-enhancement factor was calculated at various depths. It appears that Vostok ice hardens gradually with depth when considering the transverse convergent flow. No significant variation of the enhancement factor was observed with changes in climate and impurity content. Article in Journal/Newspaper Antarc* Antarctica ice core Journal of Glaciology Cambridge University Press Journal of Glaciology 35 121 392 398 |
institution |
Open Polar |
collection |
Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract Crystalline texture and c -axis orientation of the 2083 m ice core at Vostok Station, covering more than 150kyear, reveal the existence of strong anisotropics. Changes in crystal size with depth are compatible with the growth of grains driven by the free energy of grain boundaries. A smaller growth rate appears to be associated with cold periods. A gradual increase in the horizontal elongation of grains was observed between 350 and 680 m. But, the mean value of the coefficient of the linear dimensional orientation of grains does not change below 700 m. The c -axis orientation of ice grains tends to orientate perpendicular to the direction of the elongation of grains, forming a vertical girdle pattern. This characteristic fabric has been interpreted as resulting from the gradual rotation of grains by basal glide under uniaxial longitudinal tension. The rotation of grains was calculated with respect to the total strain, simulating the formation of the girdle fabric pattern. The fabric-enhancement factor was calculated at various depths. It appears that Vostok ice hardens gradually with depth when considering the transverse convergent flow. No significant variation of the enhancement factor was observed with changes in climate and impurity content. |
format |
Article in Journal/Newspaper |
author |
Lipenkov, V.Ya. Barkov, N.I. Duval, P. Pimienta, P. |
spellingShingle |
Lipenkov, V.Ya. Barkov, N.I. Duval, P. Pimienta, P. Crystalline Texture of the 2083 m Ice Core at Vostok Station, Antarctica |
author_facet |
Lipenkov, V.Ya. Barkov, N.I. Duval, P. Pimienta, P. |
author_sort |
Lipenkov, V.Ya. |
title |
Crystalline Texture of the 2083 m Ice Core at Vostok Station, Antarctica |
title_short |
Crystalline Texture of the 2083 m Ice Core at Vostok Station, Antarctica |
title_full |
Crystalline Texture of the 2083 m Ice Core at Vostok Station, Antarctica |
title_fullStr |
Crystalline Texture of the 2083 m Ice Core at Vostok Station, Antarctica |
title_full_unstemmed |
Crystalline Texture of the 2083 m Ice Core at Vostok Station, Antarctica |
title_sort |
crystalline texture of the 2083 m ice core at vostok station, antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
1989 |
url |
http://dx.doi.org/10.1017/s0022143000009321 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000009321 |
genre |
Antarc* Antarctica ice core Journal of Glaciology |
genre_facet |
Antarc* Antarctica ice core Journal of Glaciology |
op_source |
Journal of Glaciology volume 35, issue 121, page 392-398 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000009321 |
container_title |
Journal of Glaciology |
container_volume |
35 |
container_issue |
121 |
container_start_page |
392 |
op_container_end_page |
398 |
_version_ |
1810487888005038080 |