Alpine permafrost occurrence at its spatial limits: First results from the eastern margin of the European Alps

Knowledge about the occurrence and distribution of permafrost in marginal regions of the Austrian Alps is currently very limited. As a consequence, a research project has recently been initiated to model and measure permafrost occurrence in the Niedere Tauern Range, Styria. The occurrence and distribution of permafrost in the study area is discussed on the basis of small-scale modelling results as well as large-scale field validation and verification. The first results are presented here. Both implemented regional modelling approaches indicate a very low percentage of probable permafrost occurrence. Field results underline the importance of snow cover characteristics and, in particular, the spatial distribution of coarse debris for permafrost occurrence at its spatial limits. Coarse surface substrate combined with suitable snow cover conditions enable permafrost existence at a mean annual air temperature (MAAT) of 1.6°C at a selected study site. Furthermore, it can be assumed that at least some of the previously thought ‘relict’ rock glaciers in the Niedere Tauern Range are underlain by permafrost at altitudes far below modelled permafrost occurrence.

Keywords:

• Austrian Alps
• coarse debris layer
• permafrost
• thermal regime

Acknowledgements

The author expresses thanks to Gerhard Karl Lieb and Julia Eulenstein, who reviewed the text and provided constructive criticism as well as useful suggestions. Furthermore, I gratefully acknowledge the constructive and valuable comments of the two reviewers, Martin Hoelzle and Ivar Berthling, who helped to improve a former version of this article.