GEOSCAN Search Results: Fastlink


TitleEvaluation of RADARSAT-2 DInSAR seasonal surface displacement in discontinuous permafrost terrain, Yellowknife, Northwest Territories, Canada
AuthorWolfe, S A; Short, N H; Morse, P D; Schwarz, S H; Stevens, C W
SourceCanadian Journal of Remote Sensing vol. 40, no. 6, 2014 p. 406-422,
Alt SeriesEarth Sciences Sector, Contribution Series 20130466
PublisherTaylor & Francis
Mediapaper; on-line; digital
File formathtml; pdf
ProvinceNorthwest Territories
AreaYellowknife; Great Slave Lake
Lat/Long WENS-114.5000 -114.3333 62.4833 62.4333
Subjectsgeophysics; surficial geology/geomorphology; analytical methods; permafrost; displacement; radar imagery; radar methods; sediment stability; glaciolacustrine deposits; glaciofluvial deposits; subsidence; DInSAR; RADARSAT-2; Quaternary
Illustrationssketch maps; photographs
ProgramLand-based Infrastructure, Climate Change Geoscience
AbstractDifferential Interferometric Synthetic Aperture Radar (DInSAR) is an increasingly viable method for assessing permafrost terrain stability, but the accuracy and performance within discontinuous permafrost terrain has not been well studied. We used a RADARSAT-2 DInSAR data stack for a 120-day period in the summer of 2010 to map seasonal surface displacement in the discontinuous permafrost terrain of Yellowknife, Northwest Territories. Calculated displacement was compared to surficial geology and municipal land use zones. Displacement results reveal that glaciofluvial, glaciolacustrine, humanly modified, and organic terrain are increasingly unstable, in contrast to predominantly stable bedrock. Within municipal zones, increased proportional displacement is related to higher proportions of glaciolacustrine sediments and organic terrain. Organic terrain, associated with the highest proportion of the moderate downward displacement (-3.0 cm to -6.0 cm), occupies less than 6% of the total area. Widespread glaciolacustrine sediments (30% total area) are associated with most of the downward displacement in municipal zones. Semi-quantitative field and geotechnical validations indicate that most areas of moderate seasonal downward displacement in developed areas also represent areas of long-term subsidence. This work shows that even a short InSAR data stack and a simple stack processing method can yield information that is useful for municipal knowledge and planning.
Summary(Plain Language Summary, not published)
We used RADARSAT-2 DInSAR to map seasonal ground surface displacement in discontinuous permafrost in Yellowknife, Northwest Territories. Results show instability of different terrain types, with glaciolacustrine sediments and organic terrain being the most unstable units. The most stable municipal zone is Residential Mixed Density, due to comparatively higher occurrence of stable bedrock. Increasing areas of displacement within municipal zones is related to higher proportions of glaciolacustrine sediments and organic terrain. Most areas of moderate seasonal downward displacement also represent areas of long-term ground subsidence.