Early-stage interaction between settlement and temperature-gradient metamorphism
ABSTRACT Snow metamorphism and settlement change the microstructure of a snowpack simultaneously. Past experiments investigated snow deformation under isothermal conditions. In nature, temperature gradient metamorphism and settlement often occur together. We investigated snow settlement in the first...
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Cambridge University Press (CUP)
2017
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Online Access: | http://dx.doi.org/10.1017/jog.2017.31 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143017000314 |
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crcambridgeupr:10.1017/jog.2017.31 2024-09-15T18:15:39+00:00 Early-stage interaction between settlement and temperature-gradient metamorphism WIESE, MAREIKE SCHNEEBELI, MARTIN 2017 http://dx.doi.org/10.1017/jog.2017.31 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143017000314 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology volume 63, issue 240, page 652-662 ISSN 0022-1430 1727-5652 journal-article 2017 crcambridgeupr https://doi.org/10.1017/jog.2017.31 2024-06-26T04:04:03Z ABSTRACT Snow metamorphism and settlement change the microstructure of a snowpack simultaneously. Past experiments investigated snow deformation under isothermal conditions. In nature, temperature gradient metamorphism and settlement often occur together. We investigated snow settlement in the first days after the onset of temperature-gradient metamorphism in laboratory experiments by means of in-situ time-lapse micro-computed tomography. We imposed temperature gradients of up to 95 K m −1 on samples of rounded snow with a density of ~230 kg m −3 and induced settlement by applying 1.7 kPa stress with a passive load on the samples simultaneously. We found that snow settled about half as fast when a temperature gradient was present, compared with isothermal conditions. The change in specific surface area after 4 days caused by temperature-gradient metamorphism was only a few percent. The viscosity evolution correlated with the amount of the temperature gradient. Finite element simulations of the snow samples revealed that stress-bearing chains had developed in the snow structure, causing the large increase in viscosity. We could show that a small change in microstructure caused a large change in the mechanical properties. This explains the difficulty of predicting snow mechanical properties in applications such as firn compaction or snow avalanche formation. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 63 240 652 662 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
ABSTRACT Snow metamorphism and settlement change the microstructure of a snowpack simultaneously. Past experiments investigated snow deformation under isothermal conditions. In nature, temperature gradient metamorphism and settlement often occur together. We investigated snow settlement in the first days after the onset of temperature-gradient metamorphism in laboratory experiments by means of in-situ time-lapse micro-computed tomography. We imposed temperature gradients of up to 95 K m −1 on samples of rounded snow with a density of ~230 kg m −3 and induced settlement by applying 1.7 kPa stress with a passive load on the samples simultaneously. We found that snow settled about half as fast when a temperature gradient was present, compared with isothermal conditions. The change in specific surface area after 4 days caused by temperature-gradient metamorphism was only a few percent. The viscosity evolution correlated with the amount of the temperature gradient. Finite element simulations of the snow samples revealed that stress-bearing chains had developed in the snow structure, causing the large increase in viscosity. We could show that a small change in microstructure caused a large change in the mechanical properties. This explains the difficulty of predicting snow mechanical properties in applications such as firn compaction or snow avalanche formation. |
format |
Article in Journal/Newspaper |
author |
WIESE, MAREIKE SCHNEEBELI, MARTIN |
spellingShingle |
WIESE, MAREIKE SCHNEEBELI, MARTIN Early-stage interaction between settlement and temperature-gradient metamorphism |
author_facet |
WIESE, MAREIKE SCHNEEBELI, MARTIN |
author_sort |
WIESE, MAREIKE |
title |
Early-stage interaction between settlement and temperature-gradient metamorphism |
title_short |
Early-stage interaction between settlement and temperature-gradient metamorphism |
title_full |
Early-stage interaction between settlement and temperature-gradient metamorphism |
title_fullStr |
Early-stage interaction between settlement and temperature-gradient metamorphism |
title_full_unstemmed |
Early-stage interaction between settlement and temperature-gradient metamorphism |
title_sort |
early-stage interaction between settlement and temperature-gradient metamorphism |
publisher |
Cambridge University Press (CUP) |
publishDate |
2017 |
url |
http://dx.doi.org/10.1017/jog.2017.31 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143017000314 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 63, issue 240, page 652-662 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2017.31 |
container_title |
Journal of Glaciology |
container_volume |
63 |
container_issue |
240 |
container_start_page |
652 |
op_container_end_page |
662 |
_version_ |
1810453546857922560 |