EGU24-17962, updated on 11 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The impact of thermokarst development on flow and transport processes in alpine rock glaciers

Simon Seelig1, Magdalena Seelig1, Karl Krainer2, and Gerfried Winkler1
Simon Seelig et al.
  • 1University of Graz, Department of Earth Sciences, NAWI Graz Geocenter, Heinrichstraße 26, 8010 Graz, Austria (
  • 2University of Innsbruck, Department of Geology, Innrain 52, 6020 Innsbruck, Austria

Active rock glaciers represent permafrost-affected aquifers that govern the response of many alpine headwater catchments. Their heterogeneous internal structure tends to channelize groundwater flowing along the permafrost table or within the frozen rock glacier core. This study derives the hydraulic properties of such thermokarst channel systems at three active rock glaciers in the Austrian Alps. Their basic configuration is assessed through spring flow analysis and dye tracer tests. Breakthrough curves are characterized by multiple peaks and strong tailing, implying flow path separation and partial retardation of the tracer cloud travelling through the rock glaciers. Individual channels can reach diameters up to several decimeters and are characterized by a convoluted, irregular geometry. Flow along the channels is fast, highly turbulent, and characterized by high frictional resistance. Heat transfer is predominantly advective, inducing a positive feedback loop that allows larger channels to grow at the expense of smaller ones, effectively increasing the hydraulic conductivity at the rock glacier scale. The preferential flow paths provided by the thermokarst channel networks dominate flow and transport through the rock glaciers in particular during the summer months, and thus govern spring flow dynamics, solute transport, permafrost degradation, thermokarst lake outburst hazard, and rock glacier front stability.

How to cite: Seelig, S., Seelig, M., Krainer, K., and Winkler, G.: The impact of thermokarst development on flow and transport processes in alpine rock glaciers, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17962,, 2024.