The Effect of Non-Hydrostatic Stress on Intergranular Water Veins and Lenses in Ice
Abstract Polycrystalline ice at the melting point has been observed in the laboratory to contain veins of water at the places where three grains meet. Under uniaxial compression lenticular water inclusions appeared at grain boundaries perpendicular to the stress, while the nearby vein began to freez...
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Language: | English |
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Cambridge University Press (CUP)
1972
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Online Access: | http://dx.doi.org/10.1017/s0022143000022528 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000022528 |
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crcambridgeupr:10.1017/s0022143000022528 2024-03-03T08:46:06+00:00 The Effect of Non-Hydrostatic Stress on Intergranular Water Veins and Lenses in Ice Nye, J. F. Mae, S. 1972 http://dx.doi.org/10.1017/s0022143000022528 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000022528 en eng Cambridge University Press (CUP) Journal of Glaciology volume 11, issue 61, page 81-101 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1972 crcambridgeupr https://doi.org/10.1017/s0022143000022528 2024-02-08T08:37:11Z Abstract Polycrystalline ice at the melting point has been observed in the laboratory to contain veins of water at the places where three grains meet. Under uniaxial compression lenticular water inclusions appeared at grain boundaries perpendicular to the stress, while the nearby vein began to freeze. A similar effect occurred in tension on grain boundaries parallel to the stress. When the stress on the plane of the boundary was a pure shear stress, no effect was observed. The water lenses produced by stress increased in size and decreased in number after the stress was removed. The effect under compression is explained quantitatively by the combined effects of curvature and pressure on the melting point of an ice–water interface. The rate of formation of the lenses and of their coarsening is greatly reduced by the internal pressures set up in the lenses as a result of expansion on freezing and contraction on melting; transient creep to accommodate volume changes is an essential part of the process. The effect in a grain boundary under tension may arise from pressure caused by sliding on other grain boundaries; it was absent in a bicrystal. It is concluded that internal melting and freezing at grain boundaries and veins will occur in temperate glacier ice, with some effect, not discussed here, on its permeability to water. Any pure solid at its melting point which has a dihedral angle for the liquid phase in contact with a grain boundary between 0° and 60° should show similar behaviour, in that non-hydrostatic stress should cause liquid to move away from triple junctions between grains and into grain boundaries. There may be implications for the Frank theory of the upwelling of melt fluid in the Earth’s upper mantle. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 11 61 81 101 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Nye, J. F. Mae, S. The Effect of Non-Hydrostatic Stress on Intergranular Water Veins and Lenses in Ice |
topic_facet |
Earth-Surface Processes |
description |
Abstract Polycrystalline ice at the melting point has been observed in the laboratory to contain veins of water at the places where three grains meet. Under uniaxial compression lenticular water inclusions appeared at grain boundaries perpendicular to the stress, while the nearby vein began to freeze. A similar effect occurred in tension on grain boundaries parallel to the stress. When the stress on the plane of the boundary was a pure shear stress, no effect was observed. The water lenses produced by stress increased in size and decreased in number after the stress was removed. The effect under compression is explained quantitatively by the combined effects of curvature and pressure on the melting point of an ice–water interface. The rate of formation of the lenses and of their coarsening is greatly reduced by the internal pressures set up in the lenses as a result of expansion on freezing and contraction on melting; transient creep to accommodate volume changes is an essential part of the process. The effect in a grain boundary under tension may arise from pressure caused by sliding on other grain boundaries; it was absent in a bicrystal. It is concluded that internal melting and freezing at grain boundaries and veins will occur in temperate glacier ice, with some effect, not discussed here, on its permeability to water. Any pure solid at its melting point which has a dihedral angle for the liquid phase in contact with a grain boundary between 0° and 60° should show similar behaviour, in that non-hydrostatic stress should cause liquid to move away from triple junctions between grains and into grain boundaries. There may be implications for the Frank theory of the upwelling of melt fluid in the Earth’s upper mantle. |
format |
Article in Journal/Newspaper |
author |
Nye, J. F. Mae, S. |
author_facet |
Nye, J. F. Mae, S. |
author_sort |
Nye, J. F. |
title |
The Effect of Non-Hydrostatic Stress on Intergranular Water Veins and Lenses in Ice |
title_short |
The Effect of Non-Hydrostatic Stress on Intergranular Water Veins and Lenses in Ice |
title_full |
The Effect of Non-Hydrostatic Stress on Intergranular Water Veins and Lenses in Ice |
title_fullStr |
The Effect of Non-Hydrostatic Stress on Intergranular Water Veins and Lenses in Ice |
title_full_unstemmed |
The Effect of Non-Hydrostatic Stress on Intergranular Water Veins and Lenses in Ice |
title_sort |
effect of non-hydrostatic stress on intergranular water veins and lenses in ice |
publisher |
Cambridge University Press (CUP) |
publishDate |
1972 |
url |
http://dx.doi.org/10.1017/s0022143000022528 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000022528 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 11, issue 61, page 81-101 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000022528 |
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Journal of Glaciology |
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11 |
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61 |
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81 |
op_container_end_page |
101 |
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1792502001558355968 |