EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

On the dynamics of rock glaciers in marginal mountain permafrost (Retezat Mountains, Romania).

Flavius Sirbu1, Valentin Poncos2, Tazio Strozzi3, Alexandru Onaca1, Delia Teleaga2, and Dan Birtas2
Flavius Sirbu et al.
  • 1West University of Timisoara, Geography Department, Timisoara, Romania (
  • 2Terrasigna, Bucharest, Romania
  • 3Gamma Remote Sensing, Switzerland

Active rock glaciers (RG) are associated with mountain permafrost occurrence, and in the last years, remote sensing has been widely used to assess their dynamics. However, the use of remote sensing in determining the dynamics of slow-moving rock glaciers, from areas with patchy permafrost, controlled by site-specific conditions still remains a significant challenge. One such area is the central part of Retezat Mountains in the Southern Carpathians, Romania.

Here we present and discuss the results obtained by using Persistent Scatterer Interferometry (PSI) on Sentinel-1 images between 15.5.2015 and 27.10.2020. The results were validated with 26 in situ measurements with a Topcon Hiper V Differential GPS connected to the ROMPOS network for real-time corrections and millimetric accuracy. Also, the spatial distribution of RG dynamics was compared with a predicted map of permafrost distribution.

The results show that the displacement rates are low, at around 10mm/year. Out of the 48 investigated RGs, only two have displacement rates between 10 and 20mm/year, 14 show displacement of up to 10mm/year, and 32 don’t show any (measurable) displacement. However, the displacement rates are found to cover only part of the RGs, with stable areas being identified on all of them. When comparing the distribution pattern of the displacement rates, there is a good overall agreement with the modelled permafrost distribution, further suggesting that rock glacier dynamics are influenced by permafrost occurrence in marginal conditions.

How to cite: Sirbu, F., Poncos, V., Strozzi, T., Onaca, A., Teleaga, D., and Birtas, D.: On the dynamics of rock glaciers in marginal mountain permafrost (Retezat Mountains, Romania)., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7826,, 2022.