Presentation1_Thermokarst Landscape Development Detected by Multiple-Geospatial Data in Churapcha, Eastern Siberia.pdf

• Main Authors: Yoshihiro Iijima (1267884), Takahiro Abe (576295), Hitoshi Saito (2657917), Mathias Ulrich (11258412), Alexander N. Fedorov (11258418), Nikolay I. Basharin (11822789), Alexey N. Gorokhov (11822792), Victor S. Makarov (11822795)
• Format: Conference Object
• Language: unknown
• Published: 2021
• Subjects: Solid Earth Sciences; Climate Science; Atmospheric Sciences not elsewhere classified; Exploration Geochemistry; Inorganic Geochemistry; Isotope Geochemistry; Organic Geochemistry; Geochemistry not elsewhere classified; Igneous and Metamorphic Petrology; Ore Deposit Petrology; Palaeontology (incl. Palynology); Structural Geology; Tectonics; Volcanology; Geology not elsewhere classified; Seismology and Seismic Exploration; Glaciology; Hydrogeology; Natural Hazards; Quaternary Environments; Earth Sciences not elsewhere classified; Evolutionary Impacts of Climate Change; ALOS-2/PALSAR-2; UAS; interferometric SAR (InSAR); permafrost degradation; subsidence; Central Yakutia; Aldan; Churapcha; permafrost; Thermokarst; Yakutia; Siberia
• Online Access: https://doi.org/10.3389/feart.2021.750298.s001

Thermokarst is a typical process that indicates widespread permafrost degradation in yedoma landscapes. The Lena-Aldan interfluvial area in Central Yakutia in eastern Siberia is now facing extensive landscape changes with surface subsidence due to thermokarst development during the past few decades. To clarify the spatial extent and rate of subsidence, multiple spatial datasets, including GIS and remote sensing observations, were used to analyze the Churapcha rural locality, which has a typical yedoma landscape in Central Yakutia. Land cover classification maps for 1945 and 2009 provide basic information on anthropogenic disturbance to the natural landscape of boreal forest and dry grassland. Interferometric synthetic aperture radar (InSAR) with ALOS-2/PALSAR-2 data revealed activated surface subsidence of 2 cm/yr in the disturbed area, comprising mainly abandoned agricultural fields. Remote sensing with an unmanned aerial system also provided high-resolution information on polygonal relief formed by thermokarst development at a disused airfield where InSAR analysis exhibited extensive subsidence. It is worth noting that some historically deforested areas have likely recovered to the original landscape without further thermokarst development. Spatial information on historical land-use change is helpful because most areas with thermokarst development correspond to locations where land was used by humans in the past. Going forward, the integrated analysis of geospatial information will be essential for assessing permafrost degradation.