Research Perspectives on Unstable High-alpine Bedrock Permafrost: Measurement, Modelling and Process Understanding

Rock instability is believed to be causally linked to permafrost degradation, but it is difficult to demonstrate this directly because of the short record of slope failures in high mountains. While abductive scientific reasoning of 'increasing permafrost-related instability' based on the short time frame of recorded rockfall events in high mountains is still difficult, our deductive systemic understanding points toward a strong process linkage between permafrost degradation and rock instability. Enhanced technical understanding of coupled thermo-hydro-mechanical processes and systemic geomorphic understanding of rock slope adjustment in space and over (reaction/relaxation) time are required to accurately predict hazards associated with the impact of climate change on permafrost in bedrock. We identify research needs in four major areas and at the interfaces between them: rock temperature measurement and modelling; remote sensing of rock walls; process understanding of rock mass instability; and flow propagation models of rock-ice avalanches. This short communication identifies key interfaces between research directions to gain a better understanding of trajectories of destabilisation in time and space. We propose coordinated systemic research with respect to scale dependent and transient thermal behaviour, coupled thermo-hydro-mechanical understanding, enhanced remote inventorying of rock wall instability and integrated approaches for a better understanding and modelling of mixed avalanches.