Thaw subsidence can damage the infrastructure including buildings, roads and airfields founded on ice- rich permafrost, increase their maintenance costs, change the landscape and influence the sustainable development in the northern region. Information about the ground movements is important for making decisions on various geotechnical approaches to reduce impacts of permafrost degradation. However, field measurements of ground movements and long term monitoring using traditional field survey may be logistically expensive in vast and remote Northern Canada and Alaska, USA. The ability to measure surface displacements, identify the areas being impacted, and provide information of seasonal timing using remote sensing techniques would improve the knowledge and expertise of those involved in infrastructure engineering and management where permafrost is degrading. Traditional Interferometric Synthetic Aperture Radar (InSAR) measurements of deformation do not consider the effects of seasonal freeze-thaw, thus may not effectively reveal the long term trend of ground movements in permafrost region. In this paper we propose to quantitatively evaluate the seasonal ground movements resulted from on-going seasonal freezing and thawing, and estimate long term deformation of linear infrastructure in permafrost area using InSAR technique. The proposed approach has been tested on Alaska Highway built on permafrost at Beaver Creek, Yukon, Canada using Radarsat 2 data acquired during 2013-2015. Results indicate that there was long term deformation at a rate of five cm/year, in addition to an average of magnitude of vertical movement of 4 cm between winter heaving and summer thawing during annual climate cycles.

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