Analysis of summer subsidence in Barrow, Alaska, using InSAR and hyperspectral remote sensing

• Main Authors: Haghshenas Haghighi, M., Motagh, M., Heim, B., Chabrillat, S., Streletskiy, D., Grosse, G., Sachs, T., Kohnert, K.
• Format: Conference Object
• Language: English
• Published: 2016
• Subjects: Barrow; Global Terrestrial Network for Permafrost; GTN-P; permafrost; Thermokarst; Tundra; Alaska
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_1854889

In this study, gradual elevation change due to summer thawing of active layer in tundra permafrost landscape of Barrow, Alaska is investigated using SAR interferometry (InSAR) technique. We used a variety of SAR sensors including TerraSAR-X, ALOS, and Sentinel-1 images to assess elevation changes in summer season. Preliminary result, obtained by TerraSAR-X InSAR analysis, clearly delineates subsidence during the summer by identifying thousands of coherent pixels on the ground. InSAR time-series analysis from June to September 2013 show the progressive thaw-season subsidence on the Barrow coastal plain with maximum magnitude of 4 cm in satellite line of sight. The spatial pattern of InSAR elevation change reflects different thaw-related landscape features of permafrost. As a general pattern, detected elevation change is higher in wet thermokarst basins than tundra uplands. Barrow is one of the Global Terrestrial Network for Permafrost (GTN-P) sites. A lot of ancillary data that have been acquired in the last decades will help us in interpretation of InSAR results. We also use airborne hyperspectral data to derive characteristics like wetness and vegetation cover of the landscape to better understand the process and the link between estimated subsidence and landscape features.