Seasonal Progression of Ground Displacement Identified with Satellite Radar Interferometry and the Impact of Unusually Warm Conditions on Permafrost at the Yamal Peninsula in 2016

Remote Sensing

Helena Bergstedt¹  Ksenia Ermokhina²  Artem Khomutov²  Elena Babkina²  Damir Mullanurov²  Marina Leibman²  Tazio Strozzi³  Annett Bartsch⁴  Barbara Widhalm⁴  Christine Kroisleitner⁵ 

[1] Department of Geoinformatics - Z_GIS, University of Salzburg, 5020 Salzburg, Austria;Earth Cryosphere Institute, Tyumen Scientific Centre SB RAS, 625000 Tyumen, Russia;Gamma Remote Sensing, 3073 Gümligen, Switzerland;Zentralanstalt für Meteorologie und Geodynamik, 1190 Vienna, Austria;b.geos, 2100 Korneuburg, Austria;

关键词: permafrost;    subsidence;    InSAR;   

DOI  :  10.3390/rs11161865

来源: DOAJ

【 摘 要 】

Ground subsidence monitoring by Synthetic Aperture Radar interferometry (InSAR) over Arctic permafrost areas is largely limited by long revisit intervals, which can lead to signal decorrelation. Recent satellite missions such as COSMO-Skymed (X-band) and Sentinel-1 (C-band) have comparably short time intervals of a few days. We analyze dense records of COSMO-Skymed from 2013 and 2016 and of Sentinel-1 from 2016, 2017, and 2018 for the unfrozen period over central Yamal (Russia). These years were distinct in environmental conditions and 2016 in particular was unusually warm. We evaluate the InSAR-derived displacement with in situ subsidence records, active-layer thickness measurements, borehole temperature records, meteorological data, C-band scatterometer records, and a land-cover classification based on Sentinel-1 and -2 data. Our results indicate that a comparison of seasonal thaw evolution between years is feasible after accounting for the early thaw data gap in InSAR time series (as a result of snow cover) through an assessment with respect to degree-days of thawing. Average rates of subsidence agree between in situ and Sentinel-1 (corrected for viewing geometry), with 3.9 mm and 4.3 mm per 100 degree-days of thaw at the test site. X-band and C-band records agree well with each other, including seasonal evolution of subsidence. The average displacement is more than twice in magnitude at the active-layer monitoring test site in 2016 compared to the other years. We further demonstrate that InSAR displacement can not only provide information on the magnitude of ground thaw but also on soil properties through analyses of seasonal evolution in extreme years.

【 授权许可】

Unknown