Combining ALOS data and field investigations for the reconstruction of thermokarst evolution in the North Siberian Lena Delta

Anne Morgenstern(1), Mathias Ulrich(1), Frank Guenther(1), Sebastian Roessler(1) and Hugues Lantuit(1)

(1) Alfred Wegener Inst. of Polar and Marine Research, Telegrafenberg A 43, 14473 Potsdam, Germany


Our presentation will give an overview on the state of the project ‘Morphologic characterization of the Lena Delta using remote sensing and terrain modeling (LEDAM) (awarded by ESA ADEN, PI Lantuit, ID 3616). Present investigations are focused on the reconstruction of thermokarst lake and basin evolution on Kurungnakh Island in the central Lena River Delta in northeastern Siberia. This permafrost environment is characterized by thermokarst lakes and drained lake basins in sediments of the ice complex, a widely distributed phenomenon in the Siberian Arctic. Ice complex sediments consist of peat, sands, and silts with high ground ice content and are very susceptible to thermokarst processes. It is necessary to understand the detailed mechanisms of thermokarst evolution as thermokarst lakes have a great influence on permafrost landscapes under a changing climate regarding e. g. regional climate, hydrology, or carbon cycle. We combine ALOS data analysis (land cover classification, DEM generation, change detection) and field measurements (tachymetry, bathymetry, albedo, active layer, soil properties, vegetation, lake sediments) to derive detailed information on lake and basin morphology on Kurungnakh island and discriminate factors controlling it. These findings will help to assess the future evolution of thermokarst processes in ice-rich permafrost in the context of climate change.



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