Kurz- und langfristige Thermokarstdynamik in Zentraljakutien (Sibirien) aufgrund von Klimaveränderungen und anthropogenen Einflüssen

• Antragsteller: Dr. Mathias Ulrich
• Fachliche Zuordnung: Physische Geographie
• Förderung: Förderung von 2013 bis 2019
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 232311661

Ice-rich permafrost degradation is a major environmental change at high latitudes and results in the expression of characteristic periglacial hollows (thermokarst basins), which are widespread in Central Yakutia, East Siberia. Permafrost thawing due to increased air temperatures during the late Pleistocene-Holocene transition resulted in surface subsidence and the subsequent formation of thermokarst lakes and basins. The past thermokarst evolution was a dominantly climate-driven process. Today, the landscape of Central Yakutia is subject to strong short-term modifications by intensified land use, extreme weather events, and the contemporary global warming. It is not sufficiently clear, how and when thermokarst basins in Central Yakutia were formed or how they have evolved long-term trough the Holocene. It is neither clarified for the Holocene nor the short-term modern thermokarst depression and lake dynamics which climatic, morphological or hydrological parameters these are influencing. The anthropogenic aspect is of special interest for modern dynamics as human existence in this populated permafrost region is strongly connected to the use of thermokarst basins and lakes. The overarching aim of the proposed project is to reconstruct Holocene and recent permafrost degradation processes, their influencing factors and environmental impacts on long-term and short-term time-scales (millennial to sub-decadal) in the subarctic regions of Central Yakutia. On this basis, the future landscape evolution and potential hazards associated with thermokarst will be assessed. To reach this goal, an innovative approach will be performed combining remote sensing and geoinformation system (GIS) techniques with detailed geomorphological and sedimentological analyses in high temporal resolution at different thermokarst sites. At the local level, extensive field work will be carried out in order to understand small-scale variations that may arise in connection with cryolithology, relief, vegetation, hydrology, and land use. In examining the dynamics of thermokarst both the various properties as well as the diverse origins of the frozen sediments must be considered. Remote sensing methods are used and combined with detailed field knowledge to investigate thermokarst processes on large spatial scales. The Lena-Aldan-Amga region east and northeast of Yakutsk is of special interest, as this populated area is highly affected by thermokarst formations in ice-rich permafrost deposits, which are moreover highly vulnerable under a warming climate.

• DFG-Verfahren: Sachbeihilfen