Distribution of Thermokarst Lakes and Ponds at Three Yedoma Sites in Siberia

Thermokarst lake formation in ice-rich yedoma deposits in north Siberia has a major impact on regional landscape morphology, hydrology, and biogeochemistry. Detailed assessment of lake distribution characteristics is critical for understanding spatial and temporal lake dynamics and quantifying their impacts. The distribution of thermokarst ponds and lakes at three different sites with ice-rich permafrost (Bykovsky Peninsula, SW Lena Delta, and Cherskii) in northeast Siberia was analysed using high-resolution remote sensing and geographical information system (GIS) tools. Despite similarities in geocryological characteristics, the distribution of thermokarst lakes differs strongly among the study regions and is heavily influenced by the overall hydrological and geomorphologic situation as a result of past lake-landscape dynamics. By comparing our high-resolution water body dataset with existing lake inventories, we find major discrepancies in lake distribution and total coverage. The use of low-resolution lake inventories for upscaling of thermokarst lake-related environmental processes like methane emissions would result in a strong underestimation of the environmental impacts of thermokarst lakes and ponds in Arctic lowlands.