The direction of ice-wedge cracking in permafrost: downward or upward?
Field studies have been carried out along the western arctic coast of Canada in an attempt to determine whether all ice-wedge cracks originate at the ground surface and therefore propagate downward or whether some cracks originate near the top of permafrost and then propagate both upward and downwar...
Published in: | Canadian Journal of Earth Sciences |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1984
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1139/e84-056 http://www.nrcresearchpress.com/doi/pdf/10.1139/e84-056 |
id |
crcansciencepubl:10.1139/e84-056 |
---|---|
record_format |
openpolar |
spelling |
crcansciencepubl:10.1139/e84-056 2024-09-15T18:11:23+00:00 The direction of ice-wedge cracking in permafrost: downward or upward? Mackay, J. Ross 1984 http://dx.doi.org/10.1139/e84-056 http://www.nrcresearchpress.com/doi/pdf/10.1139/e84-056 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 21, issue 5, page 516-524 ISSN 0008-4077 1480-3313 journal-article 1984 crcansciencepubl https://doi.org/10.1139/e84-056 2024-07-25T04:10:03Z Field studies have been carried out along the western arctic coast of Canada in an attempt to determine whether all ice-wedge cracks originate at the ground surface and therefore propagate downward or whether some cracks originate near the top of permafrost and then propagate both upward and downward. The field studies have been concentrated upon (1) low- and high-centred tundra polygons a few thousand years old; and (2) ice wedges, growing for the first time, on the bottom of a lake experimentally drained in 1978. The field instrumentation has included electronic crack direction indicators, electronic elapsed timers, and continuous temperature measurements. The field studies reveal that many of the ice-wedge cracks originated near the top of permafrost and then propagated upward to the ground surface as well as downward into ice-wedge ice. For the 1974–1982 period, the field observations showed that about 57% of the ice wedges cracked from the ground surface downward and 43% cracked both upward and downward. Furthermore, the vertical direction of ice-wedge cracking was not consistent for any given wedge, presumably because of year-to-year variations in the physical and thermal conditions of the polygons and their troughs. Article in Journal/Newspaper Ice permafrost Tundra wedge* Canadian Science Publishing Canadian Journal of Earth Sciences 21 5 516 524 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
Field studies have been carried out along the western arctic coast of Canada in an attempt to determine whether all ice-wedge cracks originate at the ground surface and therefore propagate downward or whether some cracks originate near the top of permafrost and then propagate both upward and downward. The field studies have been concentrated upon (1) low- and high-centred tundra polygons a few thousand years old; and (2) ice wedges, growing for the first time, on the bottom of a lake experimentally drained in 1978. The field instrumentation has included electronic crack direction indicators, electronic elapsed timers, and continuous temperature measurements. The field studies reveal that many of the ice-wedge cracks originated near the top of permafrost and then propagated upward to the ground surface as well as downward into ice-wedge ice. For the 1974–1982 period, the field observations showed that about 57% of the ice wedges cracked from the ground surface downward and 43% cracked both upward and downward. Furthermore, the vertical direction of ice-wedge cracking was not consistent for any given wedge, presumably because of year-to-year variations in the physical and thermal conditions of the polygons and their troughs. |
format |
Article in Journal/Newspaper |
author |
Mackay, J. Ross |
spellingShingle |
Mackay, J. Ross The direction of ice-wedge cracking in permafrost: downward or upward? |
author_facet |
Mackay, J. Ross |
author_sort |
Mackay, J. Ross |
title |
The direction of ice-wedge cracking in permafrost: downward or upward? |
title_short |
The direction of ice-wedge cracking in permafrost: downward or upward? |
title_full |
The direction of ice-wedge cracking in permafrost: downward or upward? |
title_fullStr |
The direction of ice-wedge cracking in permafrost: downward or upward? |
title_full_unstemmed |
The direction of ice-wedge cracking in permafrost: downward or upward? |
title_sort |
direction of ice-wedge cracking in permafrost: downward or upward? |
publisher |
Canadian Science Publishing |
publishDate |
1984 |
url |
http://dx.doi.org/10.1139/e84-056 http://www.nrcresearchpress.com/doi/pdf/10.1139/e84-056 |
genre |
Ice permafrost Tundra wedge* |
genre_facet |
Ice permafrost Tundra wedge* |
op_source |
Canadian Journal of Earth Sciences volume 21, issue 5, page 516-524 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e84-056 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
21 |
container_issue |
5 |
container_start_page |
516 |
op_container_end_page |
524 |
_version_ |
1810448970746429440 |