Detecting alpine permafrost using electro-magnetic methods

In the European Alps, thawing permafrost caused by warmer temperatures has been recognised as a possible danger for slope instabilities in the past few years. The permanently frozen layer (permafrost) is often only a few metres thick. Consequently it is very vulnerable to small changes in local climate. Furthermore, the detection and localisation of such shallow permafrost sites is difficult. The heterogeneity of the material and the difficult access of the steep slopes make commonly used techniques such as reflection seismics or Ground Penetrating Radar (GPR) less adequate for alpine permafrost studies. We present preliminary results from geophysical studies within the EU-project PACE (Permafrost and Climate in Europe) which focus on a non-contact electromagnetic method to detect the distribution of mountain permafrost. The method is quick and easy to apply even in difficult terrain and on snow-covered ground. The results show that shallow permafrost lenses can be detected with only a small amount of prior information.