GEOSCAN Search Results: Fastlink

GEOSCAN Menu


TitleElectrical conductivity and ground displacement in permafrost terrain
AuthorOldenborger, G A; Short, N; LeBlanc, A -M
SourceJournal of Applied Geophysics vol. 181, 104148, 2020 p. 1-13, https://doi.org/10.1016/j.jappgeo.2020.104148
Year2020
Alt SeriesNatural Resources Canada, Contribution Series 20190052
PublisherElsevier B.V.
Documentserial
Lang.English
Mediapaper; on-line; digital
File formatpdf; html
ProvinceNunavut
AreaRankin Inlet; Kivalliq Region; Canada
Lat/Long WENS -95.0269 -79.7667 66.9300 59.7333
Subjectssurficial geology/geomorphology; geophysics; Science and Technology; Nature and Environment; permafrost; ground ice; geophysical surveys; e m surveys; conductivity surveys; remote sensing; satellite imagery; displacement; subsidence; ground temperatures; apparent conductivity; electrical resistivity tomography; differential interferometric synthetic aperture radar; DinSAR; synthetic aperture radar surveys (SAR); thaw susceptibility; permafrost thaw; climate change
Illustrationslocation maps; profiles; satellite images; geoscientific sketch maps; plots; models
ProgramClimate Change Geoscience, Permafrost
Released2020 08 03
AbstractPermafrost and ground ice are important features of the landscape that can significantly affect infrastructure in cold regions. Information on thaw susceptibility is important for predicting the behaviour of permafrost as an engineering substrate. We compare apparent conductivity surveys to ground displacement obtained from differential interferometric synthetic aperture radar with the objective of establishing apparent conductivity as an indicator of thaw susceptibility for regional characterization of terrain stability and permafrost conditions along the western coast of Hudson Bay, Nunavut. For field conditions where ground displacement and conductivity are influenced by surficial geology, there is a correlation between high seasonal and inter-annual subsidence and low apparent conductivity, and between high seasonal and inter-annual subsidence and high seasonal conductivity ratio, inferred to be indicative of high ice content and thaw-related displacement. For field conditions with no strong influence of surficial geology, a clear correspondence between subsidence and apparent conductivity does not exist. Nevertheless, the geophysical data are useful in identifying relevant factors for characterization of terrain stability such as saline permafrost and an ice-rich top of permafrost that experience significant seasonal fluctuations in unfrozen water content. When utilizing low-induction number electromagnetic surveys in permafrost terrain, apparent conductivity must be corrected for a depth-dependent temperature profile. For this study, correction factors of 6-13% are required to compensate for temperature variation, or 2.1% per °C at half-depth, but this is not necessarily applicable to other temperature profiles.
Summary(Plain Language Summary, not published)
Permafrost and ground ice are important features of the landscape that can significantly affect infrastructure in cold regions. Information on thaw susceptibility is important for predicting the behaviour of permafrost as an engineering substrate. We use geophysical data and satellite remote sensing to understand thaw susceptibility and permafrost conditions along the western coast of Hudson Bay, Nunavut. Field conditions can be complex, and there is no simple relationship between geophysical data, remote sensing, and permafrost dynamics that exists across all sites. Nevertheless, integration of information is useful for identifying relevant factors contributing to terrain stability.
GEOSCAN ID314664