GeoScience
The subsurface heat transport and hydrology in permafrost areas but also the linkage between freeze- thaw processes and destabilization of rock masses are currently poorly understood, despite their scientific and socio-economic relevance. The focus of this study is the investigation of the sensible and latent advective heat transport and water circulation and related rock movements in steep high alpine bedrock. PermaSense measurements gather information about timing and magnitude of relevant processes as well as data for model verification. Hence, the research goal of the geo-science part of PermaSense is to describe and model quantitatively the advective heat transport in clefts and in a second step to analyze the interlinkage between cleft temperatures and cleft dilatation (see figure below). Thereto heat transport processes are first investigated in single clefts (Advection 1). These findings will be transformed into a bulk-formulation for the advective heat transport in steep cold bedrock (Advection 2). An other enhancement of the study about advection in single clefts is to interlink this cleft temperatures with dilatation measurements.
Advection 1
Laboratory experiments and numerical modelling of single clefts are the basis for the analysis of the advective heat transport in clefts that are instrumented with thermistor chains (Matterhorn Hörnligrat). An example for such a model run is given in the figure below.
Crack Dilatation
The analysis of temperature dependent cleft dilatation will help to further develop the theory of high alpine weathering processes. The processes of ice-formation in clefts of cold bedrock are an important basis for the understanding of destabilisation taking place in degrading permafrost.
Advection 2
The aim of our measurement site at Jungfraujoch is to quantify the spatial variability of thawing processes and heat transport. An application of a bulk-model for the advection during the thawing period in the surface layer of steep permafrost bedrock will be validated with these measurements from Jungfraujoch.
