Project Details
Projekt
Electrical properties of frozen soil and rock
Subject Area
Geophysics
Term
since 2025
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 570259278
More than 15% of the Earth’s land surface is covered by permanently frozen ground, known as permafrost. Permafrost is threatened by climate change, posing risks to buildings, bridges, and other infrastructure. In addition, thawing permafrost can release greenhouse gases, thereby contributing to the amplification of the greenhouse effect. These emissions are particularly significant in subarctic regions, where permafrost is found in extensive peatlands. Whether, and how quickly, permafrost soils thaw due to global warming, and what the consequences are, depends on local conditions and is still not fully understood in many cases. To make scientific progress in this field, both large-scale surveys and detailed local studies are essential. In addition to boreholes and satellite measurements, geophysical methods are increasingly used to investigate the subsurface. One particularly promising technique is induced polarization, which uses alternating current to measure the frequency-dependent electrical properties of the ground. When applied with broadband signals in the frequency range around 10 kHz, this method can detect and quantify subsurface ice—a key factor for predicting the future development of permafrost soils. To fully exploit the potential of induced polarization for quantifying ice content and characterizing permafrost soils, a deeper understanding of the relationship between electrical properties and ice content is needed. For this purpose, we will conduct systematic laboratory experiments with frozen soil samples under controlled conditions. As part of this, we will collect new samples from subarctic regions with high organic content, as typically found in frozen peatlands. The results of these laboratory measurements will be analyzed using theoretical models and numerical simulations to derive general relationships between ice content and electrical properties. This will provide a fundamental understanding that is essential for the efficient and reliable characterization of permafrost soils.
DFG Programme
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