Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer
Gelifluction, thixotropy and yield stress were measured from < 5 g soil samples taken from Signy, Alectoria, Greenwich, Wiencke and Livingston islands in the maritime Antarctic using a temperature-controlled rotational rheometer. The small sample size that this method permitted is compatible with...
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Online Access: | http://nora.nerc.ac.uk/id/eprint/511026/ http://onlinelibrary.wiley.com/doi/10.1002/ppp.1886/abstract |
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ftnerc:oai:nora.nerc.ac.uk:511026 2024-01-21T10:01:09+01:00 Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer Sun, Benhua Dennis, Paul G. Newsham, Kevin K. Hopkins, David W. Hallett, Paul D. 2017-03 http://nora.nerc.ac.uk/id/eprint/511026/ http://onlinelibrary.wiley.com/doi/10.1002/ppp.1886/abstract unknown Wiley Sun, Benhua; Dennis, Paul G.; Newsham, Kevin K. orcid:0000-0002-9108-0936 Hopkins, David W.; Hallett, Paul D. 2017 Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer. Permafrost and Periglacial Processes, 28 (1). 314-321. https://doi.org/10.1002/ppp.1886 <https://doi.org/10.1002/ppp.1886> Publication - Article PeerReviewed 2017 ftnerc https://doi.org/10.1002/ppp.1886 2023-12-22T00:03:08Z Gelifluction, thixotropy and yield stress were measured from < 5 g soil samples taken from Signy, Alectoria, Greenwich, Wiencke and Livingston islands in the maritime Antarctic using a temperature-controlled rotational rheometer. The small sample size that this method permitted is compatible with sampling from sensitive sample locations. An oscillating 10 Pa shear stress was applied to samples at -0.5 kPa water potential. Two freeze-thaw cycles had temperature ramps from 5°C to -10°C over 2 h, followed by -10°C to 5°C over 2 h and finally at 5°C for 1 h. At freezing onset, the shear modulus, G, dropped to 4–50 per cent of thawed G, with no differences between locations. At thawing onset, G dropped to 8–32 per cent of thawed G, with significant differences between locations (P < 0.001). Thixotropy was then measured by applying a 2 kPa oscillating shear stress for 10 min, followed by relaxation at 10 Pa for 2 h. The increased shear stress caused G to drop to less than 8 per cent of the pre-stressed value, with no difference between locations. After 0.1 and 2 h, G was 18–65 per cent and 31–82 per cent of the pre-stressed value, respectively. A shear ramp determined yield stresses ranging from 494–2217 Pa. These findings demonstrate the potential risk of more frequent freeze-thaw cycles or the occurrence of thawed soil to the stability of polar soils. Gelifluction through more frequent freeze-thaw cycles could result in increased slope movement, whereas thixotropy caused by trampling of thawed soils could exacerbate mechanical damage of surface soils. Article in Journal/Newspaper Antarc* Antarctic Permafrost and Periglacial Processes Natural Environment Research Council: NERC Open Research Archive Antarctic Greenwich Alectoria ENVELOPE(-58.640,-58.640,-63.977,-63.977) Wiencke ENVELOPE(-63.417,-63.417,-64.500,-64.500) Permafrost and Periglacial Processes 28 1 314 321 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
Gelifluction, thixotropy and yield stress were measured from < 5 g soil samples taken from Signy, Alectoria, Greenwich, Wiencke and Livingston islands in the maritime Antarctic using a temperature-controlled rotational rheometer. The small sample size that this method permitted is compatible with sampling from sensitive sample locations. An oscillating 10 Pa shear stress was applied to samples at -0.5 kPa water potential. Two freeze-thaw cycles had temperature ramps from 5°C to -10°C over 2 h, followed by -10°C to 5°C over 2 h and finally at 5°C for 1 h. At freezing onset, the shear modulus, G, dropped to 4–50 per cent of thawed G, with no differences between locations. At thawing onset, G dropped to 8–32 per cent of thawed G, with significant differences between locations (P < 0.001). Thixotropy was then measured by applying a 2 kPa oscillating shear stress for 10 min, followed by relaxation at 10 Pa for 2 h. The increased shear stress caused G to drop to less than 8 per cent of the pre-stressed value, with no difference between locations. After 0.1 and 2 h, G was 18–65 per cent and 31–82 per cent of the pre-stressed value, respectively. A shear ramp determined yield stresses ranging from 494–2217 Pa. These findings demonstrate the potential risk of more frequent freeze-thaw cycles or the occurrence of thawed soil to the stability of polar soils. Gelifluction through more frequent freeze-thaw cycles could result in increased slope movement, whereas thixotropy caused by trampling of thawed soils could exacerbate mechanical damage of surface soils. |
format |
Article in Journal/Newspaper |
author |
Sun, Benhua Dennis, Paul G. Newsham, Kevin K. Hopkins, David W. Hallett, Paul D. |
spellingShingle |
Sun, Benhua Dennis, Paul G. Newsham, Kevin K. Hopkins, David W. Hallett, Paul D. Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer |
author_facet |
Sun, Benhua Dennis, Paul G. Newsham, Kevin K. Hopkins, David W. Hallett, Paul D. |
author_sort |
Sun, Benhua |
title |
Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer |
title_short |
Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer |
title_full |
Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer |
title_fullStr |
Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer |
title_full_unstemmed |
Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer |
title_sort |
gelifluction and thixotropy of maritime antarctic soils: small-scale measurements with a rotational rheometer |
publisher |
Wiley |
publishDate |
2017 |
url |
http://nora.nerc.ac.uk/id/eprint/511026/ http://onlinelibrary.wiley.com/doi/10.1002/ppp.1886/abstract |
long_lat |
ENVELOPE(-58.640,-58.640,-63.977,-63.977) ENVELOPE(-63.417,-63.417,-64.500,-64.500) |
geographic |
Antarctic Greenwich Alectoria Wiencke |
geographic_facet |
Antarctic Greenwich Alectoria Wiencke |
genre |
Antarc* Antarctic Permafrost and Periglacial Processes |
genre_facet |
Antarc* Antarctic Permafrost and Periglacial Processes |
op_relation |
Sun, Benhua; Dennis, Paul G.; Newsham, Kevin K. orcid:0000-0002-9108-0936 Hopkins, David W.; Hallett, Paul D. 2017 Gelifluction and thixotropy of maritime Antarctic soils: small-scale measurements with a rotational rheometer. Permafrost and Periglacial Processes, 28 (1). 314-321. https://doi.org/10.1002/ppp.1886 <https://doi.org/10.1002/ppp.1886> |
op_doi |
https://doi.org/10.1002/ppp.1886 |
container_title |
Permafrost and Periglacial Processes |
container_volume |
28 |
container_issue |
1 |
container_start_page |
314 |
op_container_end_page |
321 |
_version_ |
1788690942130126848 |