Understanding permafrost dynamics and geohazards with a terrain-cryofacies approach
Dissertation (Ph.D.) University of Alaska Fairbanks, 2021 The Arctic and its permafrost terrain are inherently dynamic, complex, and sensitive environments. Understanding the past and current changes occurring in these systems is key in predicting future variations, including the response of permafr...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/13004 2023-05-15T15:16:37+02:00 Understanding permafrost dynamics and geohazards with a terrain-cryofacies approach Stephani, Eva Shur, Yuri Doré, Guy Darrow, Margaret Kanevskiy, Mikhail 2021-12 http://hdl.handle.net/11122/13004 en_US eng http://hdl.handle.net/11122/13004 Department of Civil, Geological, and Environmental Engineering Permafrost Colville River Delta Erosion Thermokarst Doctor of Philosophy in Permafrost Geosystems: Interdisciplinary Studies Dissertation phd 2021 ftunivalaska 2023-02-23T21:38:02Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2021 The Arctic and its permafrost terrain are inherently dynamic, complex, and sensitive environments. Understanding the past and current changes occurring in these systems is key in predicting future variations, including the response of permafrost to climate change, and to terrain modifications resulting from natural processes or anthropogenic activities. This study contributes to advance our understanding of permafrost dynamics in varying permafrost environments of northern Alaska and northwestern Canada using a terrain-cryofacies approach. This unique approach helps to increase our understanding of permafrost dynamics from the site-specific scale to over extended areas by recognizing linkages between terrain and subsurface properties, and by identifying similar terrain units in remote sensing analysis. In the Colville River Delta (Alaska), our terrain-cryofacies study integrated data from 79 boreholes with a remote sensing analysis to evaluate the temporal changes in the Nigliq channel positions from 1948 to 2013 and the related permafrost dynamics. Most land cover changes occurred as land exposition (64%), whereas about 36% of the total changes were classified as eroded. The erosion of the older terrain units from the floodplain toposequence, such as the inactive-floodplain cover deposits, implied ground loss volumes of about one-fifth of soil solids and four-fifths of ground ice. Along this channel, we also identified the typical configuration and properties of taliks and cryopegs, as well as subsequent epigenetic permafrost growth. We found that the active channel was underlain by closed taliks, rather than through taliks and thus did not penetrate the entire layer of permafrost connecting supra- and sub-permafrost groundwater. A cryopeg connected to the active channel talik was identified from borehole data in the adjacent terrain units that developed following channel migration. We estimated the likelihood of encountering such taliks and cryopegs ... Doctoral or Postdoctoral Thesis Arctic Climate change Ice permafrost Thermokarst Alaska University of Alaska: ScholarWorks@UA Arctic Canada Fairbanks Talik ENVELOPE(146.601,146.601,59.667,59.667) |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
Permafrost Colville River Delta Erosion Thermokarst Doctor of Philosophy in Permafrost Geosystems: Interdisciplinary Studies |
spellingShingle |
Permafrost Colville River Delta Erosion Thermokarst Doctor of Philosophy in Permafrost Geosystems: Interdisciplinary Studies Stephani, Eva Understanding permafrost dynamics and geohazards with a terrain-cryofacies approach |
topic_facet |
Permafrost Colville River Delta Erosion Thermokarst Doctor of Philosophy in Permafrost Geosystems: Interdisciplinary Studies |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 2021 The Arctic and its permafrost terrain are inherently dynamic, complex, and sensitive environments. Understanding the past and current changes occurring in these systems is key in predicting future variations, including the response of permafrost to climate change, and to terrain modifications resulting from natural processes or anthropogenic activities. This study contributes to advance our understanding of permafrost dynamics in varying permafrost environments of northern Alaska and northwestern Canada using a terrain-cryofacies approach. This unique approach helps to increase our understanding of permafrost dynamics from the site-specific scale to over extended areas by recognizing linkages between terrain and subsurface properties, and by identifying similar terrain units in remote sensing analysis. In the Colville River Delta (Alaska), our terrain-cryofacies study integrated data from 79 boreholes with a remote sensing analysis to evaluate the temporal changes in the Nigliq channel positions from 1948 to 2013 and the related permafrost dynamics. Most land cover changes occurred as land exposition (64%), whereas about 36% of the total changes were classified as eroded. The erosion of the older terrain units from the floodplain toposequence, such as the inactive-floodplain cover deposits, implied ground loss volumes of about one-fifth of soil solids and four-fifths of ground ice. Along this channel, we also identified the typical configuration and properties of taliks and cryopegs, as well as subsequent epigenetic permafrost growth. We found that the active channel was underlain by closed taliks, rather than through taliks and thus did not penetrate the entire layer of permafrost connecting supra- and sub-permafrost groundwater. A cryopeg connected to the active channel talik was identified from borehole data in the adjacent terrain units that developed following channel migration. We estimated the likelihood of encountering such taliks and cryopegs ... |
author2 |
Shur, Yuri Doré, Guy Darrow, Margaret Kanevskiy, Mikhail |
format |
Doctoral or Postdoctoral Thesis |
author |
Stephani, Eva |
author_facet |
Stephani, Eva |
author_sort |
Stephani, Eva |
title |
Understanding permafrost dynamics and geohazards with a terrain-cryofacies approach |
title_short |
Understanding permafrost dynamics and geohazards with a terrain-cryofacies approach |
title_full |
Understanding permafrost dynamics and geohazards with a terrain-cryofacies approach |
title_fullStr |
Understanding permafrost dynamics and geohazards with a terrain-cryofacies approach |
title_full_unstemmed |
Understanding permafrost dynamics and geohazards with a terrain-cryofacies approach |
title_sort |
understanding permafrost dynamics and geohazards with a terrain-cryofacies approach |
publishDate |
2021 |
url |
http://hdl.handle.net/11122/13004 |
long_lat |
ENVELOPE(146.601,146.601,59.667,59.667) |
geographic |
Arctic Canada Fairbanks Talik |
geographic_facet |
Arctic Canada Fairbanks Talik |
genre |
Arctic Climate change Ice permafrost Thermokarst Alaska |
genre_facet |
Arctic Climate change Ice permafrost Thermokarst Alaska |
op_relation |
http://hdl.handle.net/11122/13004 Department of Civil, Geological, and Environmental Engineering |
_version_ |
1766346926893039616 |