Seasonal dynamics of a permafrost landscape, Adventdalen, Svalbard, investigated by InSAR

REMOTE SENSING OF ENVIRONMENT

卷:231

Article

Rouyet, Line^1,2,3  Lauknes, Tom Rune¹  Christiansen, Hanne H.³  Strand, Sarah M.^3,4  Larsen, Yngvar¹ 

[1] NORCE Norwegian Res Ctr AS, Siva Innovasjonssenter, POB 6434, N-9294 Tromso, Norway

[2] Arctic Univ Norway UiT, Dept Geosci, POB 6050, N-9037 Tromso, Norway

[3] Univ Ctr Svalbard UNIS, Arctic Geol Dept, POB 156, N-9171 Longyearbyen, Norway

[4] Univ Oslo UiO, Dept Geosci, POB 1047, N-0316 Oslo, Norway

关键词: InSAR;    Permafrost Svalbard;    Arctic;    Thaw subsidence;    Frost heave;    Creep;    Periglacial landforms;   

DOI  :  10.1016/j.rse.2019.111236

来源: Elsevier

【 摘 要 】

Nordenskiold Land in Central Spitsbergen, Svalbard is characterized as a high latitude, high relief periglacial landscape with permafrost occurring both in mountains and lowlands. Freezing and thawing of the active layer causes seasonal frost heave and thaw subsidence, while permafrost-related mass-wasting processes induce downslope ground displacements on valley sides. Displacement rate varies spatially and temporally depending on environmental factors. In our study, we apply Satellite Synthetic Aperture Radar Interferometry (InSAR) to investigate the magnitude, spatial distribution and timing of seasonal ground displacements in and around Adventdalen using TerraSAR-X StripMap Mode (2009-2017) and Sentinel-1 Interferometric Wide Swath Mode (2015-2017) SAR images. First, we show that InSAR results from both sensors highlight consistent patterns and provide a comprehensive overview of the distribution of displacement rates. Secondly, two-dimensional (2D) TerraSAR-X InSAR results from combined ascending and descending geometries document the spatial variability of the vertical and east-west horizontal displacement rates for an average of nine thawing seasons. The remote sensing results are compared to a simplified geomorphological map enabling the identification of specific magnitudes and orientations of displacements for 14 selected geomorphological units. Finally, June to December 2017 6-day sampling interval Sentinel-1 time series was retrieved and compared to active layer ground temperatures from two boreholes. The timing of the subsidence and heave detected by InSAR matches the thawing and freeze-back periods measured by in-situ sensors. Our results highlight the value of InSAR to obtain landscape scale knowledge about the seasonal dynamics of complex periglacial environments.

【 授权许可】

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