The local organising committee is busy with the preparation of the 8th International Conference on Permafrost to be held in 2003 in Zurich. We are looking forward to welcome the permafrost community next July in Switzerland.
The ‘Permafrost Monitoring Switzerland’, PERMOS, continued its activities within the pilot phase 2001-2003. The fi rst annual report was published. Two working groups, one for the 12 boreholes and one for the 10 BTS areas, were established to coordinate and standardise data sets. A second report is being edited and data will be published according to suggestions of the working groups.
In 2002 three permafrost-related Ph.D. theses were fi nished: Catherine Stocker-Mittaz, University of Zurich ‘Permafrost distribution modelling based on energy-balance data’, Martin Musil, ETH Zurich, ‘Inverting seismic and georadar data with applications to the Muragl rock glacier’ and Lukas Arenson, ETH Zurich ‘Unstable Alpine permafrost: A potentially important natural hazard. Variations of geotechnical behaviour with time and temperature’.
At the Swiss Federal Institute for Snow and Avalanche Research Marcia Phillips is investigating low-lying permafrost sites located below the limit of alpine permafrost, in collaboration with several other research institutes. The sites are scree slopes at the base of high cliffs and are characterised by having exceptionally cold ground temperatures. Trees growing on these slopes are highly stunted. Soil and tree-ring analyses and ground temperature measurements are carried out to investigate the reasons for the reduced growth of the trees. The stability of avalanche defence structures on steep slopes in alpine permafrost terrain continues to be monitored. The structures at three experimental sites are creeping downslope at rates exceeding those approved by the Swiss Federal Guidelines and various types of foundations are increasingly being put to the test. Two, 20-m deep boreholes were drilled in the avalanche slope at Flüelapass, behind lake Schotten, in the project ‘Snow cover and permafrost’ by Martina Lütschg and Veronika Stöckli, aiming at a numerical study of the interaction processes between snow cover and permafrost.
New projects of the Glaciology and Geomorphodynamics Group at the Geography Department, University of Zurich focus on energy fl ux processes in the active layer (Susanne Hanson, Martin Hoelzle), quantitative remote sensing for spatial permafrost modelling (Stephan Gruber, Daniel Schläpfer) and parameterization of rock-wall temperatures (Stephan Gruber, Wilfried Haeberli). Five, 5-m deep boreholes at sites with different surface characteristics were drilled in the Murtèl-Corvatsch area. The use of hyperspectral remote sensing in high-mountain permafrost has been pioneered by a successful fl ight of DAIS7915 in the Murtèl-Corvatsch test area. A set of 22 miniature temperature dataloggers has been installed in near-vertical rock faces of different aspect between 2000 and 4500 m asl.
In collaboration with the Institute for Meteorology and Climate Research, University of Karlsruhe, Germany (Christian Hauck), the Glaciology and Geomorphodynamics Group at the Geography Department, University of Zurich (Lars Schudel, Martin Hoelzle) continues permafrost monitoring on Schilthorn with combined geophysical and meteorological measurements. This work started during the PACE project and aims to quantify the energy exchange processes between the atmosphere and the shallow subsurface related to ground freezing and thawing. Permanently installed electrodes for electrical resistivity monitoring (determining the unfrozen water content), an energy balance station and instrumented PACE boreholes for temperature measurements are used. In addition, the data serve as input and validation variables for 1-dimensional modelling of energy and water fl uxes in frozen soil.
The investigations on the two rock glaciers Muragl and Murtèl-Corvatsch within the ETHMini- Poly project (Sarah Springman, Hansruedi Maurer, Daniel Vonder Mühll, Lukas Arenson, Martin Musil) were completed except for ongoing temperature monitoring within fi ve boreholes and borehole deformation measurements at the second location. The geophysical cross-hole georadar experiments at Muragl showed very good consistency with the internal structure from the drillings and it was possible to estimate the location of the shear zone. The laboratory investigations, triaxial creep and shear tests on permafrost samples, revealed new information concerning the behaviour of ice-rich frozen soil with high volumetric air content under various loading conditions. Together with the fi eld observations, these results were used to develop general statements about the stability of rock glaciers. In addition, thermal anomalies have been measured within both rock glaciers, revealing air and water circulation at the base but also through open channels within the permafrost, which may result in accelerated permafrost degradation.
The Institutes of Geography of the Universities of Lausanne (Christophe Lambiel, Emmanuel Reynard) and Fribourg (Reynald Delaloye, Alain Turatti, Sébastien Métrailler) continue their collaboration mainly in the Valais Alps. Frozen scree slopes at very different altitudinal ranges are the subject of thermal and geoelectrical measurements. Glacier forefi elds are investigated to understand the glacierpermafrost relationships in the Verbier area. In the Réchy/Lona region, electrical soundings and BTS measurements in two small glacier forefi elds carried out in 1990 are compared with modern data in collaboration with the University Institute Kurt Bösch at Sion (R. Lugon). Rock glaciers movement have been measured with a differential GPS. First results show velocities up to 125 cm/year in a rock glacier with low resistivity ice, whereas an adjacent rock glacier containing high resistivity ice only moved 30 cm/year.
Daniel Vonder Mühll (Daniel.VonderMuehll@unibas.ch)