Neue Forschungsansätze zur räumlichen und zeitlichen Dynamik des Gebirgspermafrosts und dessen Naturgefahrenpotentials

Permafrost changes the thermal, hydraulic, and mechanic behaviour of permanently frozen debris and bedrock in high mountains. This results in a suite of typical geomorphological processes including enhanced ice segregation and ice creep, which act to generate landforms such as rock glaciers and (ice-supported) sagging rock slopes in permafrost areas. Correspondingly, there is a certain potential of natural hazards due to rapid fall processes detaching from rock walls and rock glaciers, due to continuous creep deformation and due to indirect effects e.g. on debris flow activity, glacial lake outburst floods and the flow regime of rivers. The warm permafrost in the Alps reacts sensitive to small alterations of climatic parameters such as air temperature, radiation balance, duration and timing of snow cover. First indications of the reaction of permafrost systems to the warm summer 2003 and the warm winter 2006/2007 are provided by surface and subsurface temperature measurements in the Alps, many of which are now systematically organized in monitoring networks. Besides, we identify four upcoming research approaches: (i) spatial characterization of permafrost and ice content in different landforms, (ii) (long-term) temporal monitoring and quantification of permafrost dynamics, ice content and thermal behaviour, (iii) kinematic assessment of instable permafrost slopes and rocks as well as geomechanical process analysis and (iv) modelling of permafrost evolution applying different scenarios of climate change. These research schemes aim at developing an enhanced understanding of the trajectories of permafrost degradation and the related destabilization processes, in order to better anticipate the effects of climate change and the connected changes in the hazard potential. Research approaches of polar and alpine permafrost research could be better coupled in future to combine complementary concepts in different process, time and space scales.