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TitleDInSAR interannual seasonal surface displacement in permafrost terrain, Iqaluit, Nunavut
LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorLeBlanc, A -MORCID logo; Short, NORCID logo; Mathon-Dufour, V; Chartrand, JORCID logo
SourceGeological Survey of Canada, Open File 7874, 2015, 36 pages, Open Access logo Open Access
PublisherNatural Resources Canada
Documentopen file
Mediaon-line; digital
File formatreadme
File formatpdf; rtf; xml; ovr; tif
NTS25N/09NW; 25N/10NE; 25N/15SE; 25N/16SW
Lat/Long WENS-68.5833 -68.4167 63.8333 63.6667
Subjectssurficial geology/geomorphology; soils science; geophysics; Nature and Environment; displacement; sediment transport; glacial features; glacial deposits; freezing ground; ground ice; ground temperatures; permafrost; climatic fluctuations; climate, arctic; soils; soil types; remote sensing; terrain sensitivity; terrain analysis; RADARSAT-2; DInSAR; Cenozoic; Quaternary
Illustrationstables; location maps; plots; histograms; photographs
ProgramClimate Change Geoscience Land-based Infrastructure
Released2015 12 04
Monitoring permafrost dynamics over large areas is challenging. In recent years, interest in the use of Interferometric Synthetic Aperture Radar (InSAR) as a source of surface displacement information for permafrost environments has increased considerably. Among the available InSAR methods, conventional differential InSAR (DInSAR) makes it possible to detect very small ground surface movement, on the order of centimetres, for every pixel over large areas, providing a way to assess active layer and permafrost dynamics. In order to expand existing knowledge and guide potential applications of DInSAR, three consecutive years of seasonal surface displacement in Iqaluit, Nunavut, were analysed along with surficial units, permafrost and climatic data, and compared for built and natural environments. RADARSAT-2 spotlight scenes with a resolution of approximately 1 m were used to create maps of seasonal ground surface displacement. Results show that surficial geology and ground ice are essential information to interpret DInSAR results: low displacement is associated with bedrock and coarse sediments, while finer sediments, more likely to be ice-rich, show higher values of displacement. Other factors such as water at the surface and mapping scale of surficial deposits, can explain some displacement patterns. One DInSAR season could be used to identify difficult terrain for construction. However, displacement values for a given area can vary from one year to the next due to annual climatic conditions. Therefore, more than one season helps to differentiate between different causes of displacement. For a given surficial geology unit, displacements were generally lower in built areas than in the natural environment due to granular fill or pads and construction methods. Findings from this study are useful to guide DInSAR applications especially for infrastructure management and planning.
Summary(Plain Language Summary, not published)
Satellite radar data can be carefully processed to reveal movement of the ground in permafrost areas. These patterns of movement can be linked to the ground conditions and therefore be used to support decision-making for existing or new infrastructures. Three consecutive years of satellite radar data over Iqaluit in Nunavut, are analysed to highlight the similarities and the differences between the results. Results are also examined in conjunction with surficial deposits for natural and built environments. Patterns of movement are similar between years; however, the magnitude of movement for a given area can vary according to annual climatic conditions. According to the results of this research, the use of materials and methods of construction in built environments has a positive effect by lowering the values of ground movement.

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