| Title | Electrical conductivity and ground displacement in permafrost terrain |
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| Author | Oldenborger, G A ;
Short, N; LeBlanc, A -M |
| Source | Journal of Applied Geophysics vol. 181, 104148, 2020 p. 1-13, https://doi.org/10.1016/j.jappgeo.2020.104148 |
| Image |  |
| Year | 2020 |
| Alt Series | Natural Resources Canada, Contribution Series 20190052 |
| Publisher | Elsevier B.V. |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html |
| Province | Nunavut |
| Area | Rankin Inlet; Kivalliq Region; Canada |
| Lat/Long WENS | -95.0269 -79.7667 66.9300 59.7333 |
| Subjects | surficial 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; synthetic aperture radar surveys (SAR); permafrost thaw; Climate change |
| Illustrations | location maps; profiles; satellite images; geoscientific sketch maps; plots; models |
| Program | Climate Change
Geoscience Permafrost |
| Released | 2020 08 03 |
| Abstract | 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 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 ID | 314664 |
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