Multi-methodological three-dimensional investigation of open- and closed-system Pingos in northwestern Canada (Pingo3D)

• Applicant: Professor Dr. Christof Kneisel
• Subject Area: Physical Geography
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 515411322

Pingos are one of the most important landforms in the Arctic and are key features of polar permafrost landscapes. They are sensitive to changing climatic and hydrological conditions, which is why their spatial distribution is likely to change significantly in the course of current global warming. This is due to higher temperatures but also to changing permafrost hydrology, which plays an essential role during formation, but also during decay of pingos. The project aims to gain new insights into the internal structure of open- and closed-system pingos and their genesis by using a combined approach of three-dimensional geophysical measurements and various in-situ data. Possible interactions between surface and subsurface properties are the main focus. Geoelectrics, induced polarisation, georadar and potentially electromagnetic will be used to perform the three-dimensional geophysical investigations, as they allow a high-resolution characterization of the near-surface subsurface as well as a good delineation between frozen and unfrozen areas. In addition, surface temperature loggers and several boreholes will be used to investigate the spatiotemporal variability of the thermal regime. Surface parameters include various topographic features such as vegetation type and height. These surface parameters will be determined using high-resolution, drone-based terrain models and orthophotos and examined for changes over the course of the project. Long-term changes will be additionally captured by a time series analysis of Landsat data as well as a deformation analysis based on an InSAR evaluation. Local surface hydrology and hydrology within the active layer will also be investigated and modelled as another link between surface and subsurface hydrology. The combined approach of three-dimensional geophysics, remote sensing methods, hydrological modelling and various in situ datasets will allow detailed investigation of the internal structures of pingos while exploring the complex interactions between surface and subsurface processes. The synthesis includes the identification of variables influencing surface and subsurface conditions and any interactions between surface and subsurface parameters. The holistic approach will enable the development of improved conceptual 3D models of pingo genesis to explain the cryo-hydrogeologic processes that occur in Arctic geosystems. These processes are elemental to the life cycle of pingos, but are also important in other Arctic permafrost landscapes. Based on these findings, site-specific scenarios for future permafrost dynamics and their impacts on landforms can be developed. In addition, based on the expected results of the combined methodological approach, the broader scientific significance of the study lies in the ability to establish best-practices for investigating zones of unfrozen ground in permafrost regions and to better understand the complex permafrost hydrology.

• DFG Programme: Research Grants