The concept Permafrost Monitoring Switzerland (PERMOS) was approved by the Swiss Co-ordinating Group for Permafrost in November 1999 and ratified by the Glaciological Commission of the Swiss Academy of Sciences (SAS) in January 2000.
During a pilot phase lasting from 2000 to 2003, the activities will be concentrated to circa 10 existing drillings, 10 permafrost distribution areas and a maximum of two aerial flights per year. Measurements are undertaken by eight institutes that actually set up the various sites. Meanwhile, efforts are under way to associate PERMOS under the umbrella of a federal department to ensure the long-term financing and maintenance of the network.
Mountain permafrost research is undertaken by various institutes, some of the projects with collaboration of two or more institutes are as follows: The Institutes of Geography at the Universties of Lausanne (IGUL, Emmanuel Reynard, Christophe Lambiel) and Fribourg (IGUF, Michel Monbaron, Reynald Delaloye, Grégoire Devaud) are conducting several projects on the distribution and thermal conditions of discontinuous permafrost in the western part of Switzerland. In the partially frozen talus slope of the Lapires (Mont-Gelé, 2500 m asl.), measurements in the 20 m deep borehole drilled in autumn 1998 indicate permafrost with temperature close to the melting point (temperatures between –0.2ºC and 0ºC), an active layer of 3 m and a ZAA (zero annual amplitude) depth of only 4 m ! At the Alpage de Mille (2200 – 2450 m asl.) analyses of spatial and temporal variability of BTS measurements are conducted in the vicinity of two inactive rock glaciers since 1996. Investigations on permafrost-glacier relationships in several sites indicate, beneath the high complexity of such terrain, the degradation, displacement and even the whole melting of pre-Little Ice Age frozen bodies, the possible post-Little Ice Age establishment of permafrost, and finally, in the forefield of the Grand-Aget glacier (2800 m asl.) a landslide affecting frozen material. Mapping of past, current and future distribution of permafrost and glaciers in the Mont-Gelé area is carried out. Geophysical survey (tomography, DC resistivity soundings) and BTS measurements are performed in frozen terrain (rock glaciers, moraines, proglacial margins, screes) in the same area. Both institutes are also investigating the thermal evolution of perennially frozen ground at very low elevations (Creux du Van, Jura Range, 1200 m asl.) in collaboration with SFISAR, Davos (Veronica Stöckli, Marcia Phillips). Dendrochronological curves are compared with the thermal conditions of the ground.
The University of Bern (Group for Applied Geomorphology) has been investigating permafrost and periglacial phenomena in the small valley Furggentälti in the Gemmi region (2500 m. asl., Wallis, Switzerland) for many years. In 2000, the work concentrated on the new meteorological stations (radiation and energy balance, standard climate parameters) (Hans Kienholz, Severin Schwab, Dragan Mihajlovic). Furthermore, the annual BTS campaign was carried out last winter, combined with BTS measurements from more than 40, single-channel temperature data loggers. The two projects concerning the flow dynamics of the rock glacier in the Furggentälti (Dorothea Koelbing) and the spatial and temporal dynamics of the snow cover (Isabelle Kunz) are almost finished.
To improve understanding of the effects of disastrous flooding caused by high air temperature linked with heavy precipitation, a joint study between the Geological Laboratory of the EPFL (GEOLEP, Daniel Bayard) and the Institute of Terrestrial Ecology (ITÖ- ETHZ, Hannes Flühler, Manfred Stähli) is being conducted during the winter 2000/2001. This project called “Water infiltration in a partly frozen soil and ground water recharge in alpine catchments” combines physical and hydrogeological aspects to study water dynamics into a partly frozen soil in a mountainous area. Field experiments collecting meteorological data and soil physical data will serve as inputs for a numerical model. A one-dimensional heat- and water-balance model will be used for predicting the influence of the greenhouse effect on the studied system. Experiments will be carried out at various places in the southern Swiss Alps (region of the Valais), at the Hannigalp near Grächen (at 2100 m asl.) and near the Gd St Bernard pass (2500 m asl.) to characterise the hydrogeological processes for different climates and to investigate the influence of site orientation, altitude and soil texture on the frost depths and amount of percolated water. Tracer experiments will be used to quantify snow melt infiltration into frozen ground and to investigate the dependence of frozen soil infiltration on soil properties, surface characteristics and physical state at the onset of the snow melt.
The University of Zürich (Regula Frauenfelder, Wilfried Haeberli, Andi Kääb, Martin Hoelzle) is involved in several projects related to mountain permafrost. Digital photogrammetry, geodesy, remote sensing and geomorphology focus on improved process understanding of glacial and periglacial hazards. In the project “GIS-based Modelling of Creeping Mountain Permafrost” supported by the Foundation for the Promotion of Scientific Research at the University of Zürich, rock glaciers are of particular interest. Due to the fact that only the ice of a rock glacier matrix can melt, rock glacier topography is a cumulative expression of the entire rock glacier history and, thus, in a complex way, of the present and past environment. The decoding of present-day morphology and distribution of rock glaciers, and a better knowledge of the climatic controls on rock glaciers provide important information on past and present climate conditions. So far few investigations exist about regional variability of rock glacier development, i.e. what regional effects cause rock glacier abundance in contrast to scarce distribution of such a phenomenon. The project aims at closing this gap by applying two complementary approaches: (a) the development of a GISbased model simulating alpine rock glacier distribution and (b) the evaluation of presently relict rock glaciers to reconstruct past distribution of permafrost limits. The synthesis of these two approaches should allow for assessing palaeoclimatic fluctuations in the time range of millennia.
The ETH-Mini-Poly project of the three institutes Geotechnics (Sarah Springman, Lukas Arenson), Geophysics (Hansruedi Maurer, Martin Musil) and VAW (Daniel Vonder Mühll) continued in its second year. After drilling four, 70 m deep boreholes through the Muragl rock glacier in 1999, two new cored drillings were undertaken this year on Murtèl-Corvatsch rock glacier. The boreholes are some 15 and 35 m upslope of the borehole 2/1987, and are 51 and 63 m deep. Undisturbed cores of frozen material for laboratory testing were taken and determination of in situ strength and stiffness using a pressuremeter (Cambridge InSitu) were performed. In addition, instruments for longterm monitoring of deformation and temperature were installed. The first results of the field measurements and some additional triaxial tests on artificially frozen samples, indicate that the thermo-mechanical behaviour of ice-rich permafrost soil close to 0ºC strongly depends on micromechanical processes. Interaction between the air voids, the ice, the soil particles and the unfrozen water has to be taken into account while describing failure or creeping processes of such a system. Therefore, the stability of some currently frozen alpine slopes is thought to be extremely sensitive to climate change. First assumptions can be made, but in order to be able to predict the probability of slope failure, further laboratory investigations and numerical analyses are necessary.
Within the PACE project, the two Swiss partners (University of Zürich: Wilfried Haeberli, Martin Hoelzle, Catherine Mittaz; VAW-ETH Zürich: Daniel VonderMühll, Christian Hauck) drilled two, 101 m deep boreholes (a vertical and an oblique one) at the north slope of Schilthorn. Further, geophysical field survey at various PACE drill sites (VAW) and energy balance measurements were undertaken during the past year. The latter allows improving the permafrost distribution models taking into account effects of snow and thermal offset.
During the last year, Marcia Phillips finished her PhD entitled ‘Snow supporting structures in permafrost terrain’ at the SFISAR, Davos.
Daniel Vonder Mühll (Daniel.VonderMuehll@unibas.ch)