In the last year, the main issue of the Glaciological Commission of the Swiss Academy of Sciences (SAS) has been permafrost, in particular the concept of the Permafrost Monitoring Switzerland (PERMOS). It was agreed that the main part will comprise thermal monitoring in a number of shallow, 20 m deep boreholes. Various existing sites form the base, which will be enlarged continuously. In January 1999, a meeting held in Interlaken was dedicated to permafrost with presentations by Charles Harris (Permafrost and Climate in Europe - PACE), Markus Imhof (Permafrost in the Schilthorn region), Hansruedi Keusen (Geotechnical approaches for buildings in permafrost) and Daniel Vonder Mühll (Permafrost Monitoring Switzerland - PERMOS).
The International Glaciological Society (IGS) held a meeting in August 1999 in Zürich. Five talks were given in the permafrost session and several permafrost posters were presented. A field trip led by Wilfried Haeberli and Marcia Phillips took the participants to the Swiss Federal Institute for Snow and Avalanche Research (SFISAR, Davos) and various research sites in the Upper Engadin.
The results of the project ‘Ice melt in high mountain areas ’ (Project W. Haeberli) within the National Research Program me (NRP) 31 on ‘Climate Change and Natural W. Hazards’, was published in spring 1999.
Within the Hydrological Atlas of Switzerland (HADES), the permafrost part was published in August 1999. It contains a Swiss map showing the permafrost distribution according to three different models, the location of over one hundred rock glaciers, three case studies (Murtèl-Corvatsch, Furggentälti and Val Réchy) and a comment in German, French, Italian and English. Meanwhile, projects performed through several institutes are going on: The Institutes of Geography at Fribourg (IGUF, Michel Monbaron, Jean-Michel Gardaz, Reynard Delaloye) and Lausanne (IGUL, Emmanual Reynard) are conducting research on the thermal evolution of permanently frozen ground at very low elevations (Creux du Van, Jura Range, 1200m asl.) and at the lower limit of the discontinuous permafrost belt in the western Penninic Alps (Alpage de Mille, 2300m asl.; Mont-Gele/Lapires, 2500m asl.). A comparative study site of IGUL is situated in the more oceanic Diablerets region (2400m asl). Various methods such as direct current (DC) resistivity soundings and mapping, BTS measurements, and continuous temperature measurements at the ground surface are being used. In the Lapires talus slope, a 20 m borehole was drilled in autumn 1998.
The research project ‘Snow-supporting structures in permafrost terrain’ has been running for three years at the SFISAR, Davos (Patrik Thalparpan, Marcia Phillips). The influence of snow-supporting structures on ground temperature evolution, and the technical aspects of the construction of the structures in high alpine permafrost terrain are being investigated. Field measurements include the monitoring of borehole temperatures, snow distribution, temperatures of experimental snow-supporting structures, and slope stability. Results obtained from measurements and computer simulations indicate that heat is not conducted into or out of the ground through the steel components of the supporting structures. Ground temperature is, however, reduced slightly on a very local scale through artificial modification of snow cover distribution. Temperature measurements will be continued to verify these results over a longer period. Several types of structures and foundations have been tested for their suitability in steep, potentially unstable terrain. In addition, anchor pull-out tests were conducted and different types of grout and injection techniques were investigated in the field and in the laboratory. Guidelines for the construction of snow-supporting structures in permafrost have been established.
At the Department of Geography, University of Zürich (Wilfried Haeberli, Andi Kääb, Martin Hoelzle), various ongoing projects relate to creeping mountain permafrost. They combine photogrammetry, geodesy, geophysics, geomorphology and distribution modelling. One project aims at developing remote sensing techniques for early recognition of glacial and periglacial hazards based on satellite imagery, aerial photography and digital terrain models. On Muragl rock glacier, four 70m deep boreholes some 30m apart, were drilled within the ETH-Mini-Poly project of the three institutes of Geotechnics (Sarah Springman, Lukas Arenson), Geophysics (Hansruedi Maurer, Martin Musil) and VAW (Daniel Vonder Mühll). Sophisticated geophysical surveys included both surface as well as borehole-to-borehole investigations (seismics and radar). Some cores were saved and are being analysed. Borehole logging, vertical and horizontal deformation and temperatures provide the base to assess the geotechnical characteristics, and for long-term monitoring of the rock glacier.
As the PACE project is fully operative now, the main fieldwork at all field sites took place this year. The two Swiss partners (University of Zürich: Wilfried Haeberli, Martin Hoelzle, Catherine Mittaz; VAW-ETH Zürich: Daniel Vonder Mühll, Christian Hauck) intensified their investigation at the Schilthorn site: geophysical surveys, a 14 m deep borehole to measure temperatures and a climate station to determine the energy balance are a first step to the deep drilling, which will be done in 2000. VAW-ETH Zurich organised and participated in the geophysical fieldwork in Sierra Nevada (Spain), Svalbard, Tarfala (Sweden), Valtellina (Italy), Jotunheimen (Norway) and at various sites in the Swiss Alps. A whole range of different methods were used, such as refraction seismics, DC resistivity tomography and various electromagnetic methods in order to evaluate sui-table techniques for the mapping of permafrost. First results were presented at the PACE meeting in Giessen, Germany in October 1999. Possible new establishment of permafrost in glacier forefields is investigated at the Muragl glacier by the University of Trier, Germany (Christoph Kneisel), and in several glacier forefields in the Valais area by the University of Fribourg (Reynald Delaloye).
Three PhD theses were successfully completed during the last year: Markus Imhof (University of Berne) investigated the relationship between permafrost and snow especially in the Bernese Alps, including the Schilthorn area. Emmanuel Reynard (University of Lausanne) performed geomorphological and hydrological studies in the Montana area (Valais). Jean-Michel Gardaz (University of Fribourg) wrote his thesis about hydrology in permafrost.
Daniel Vonder Mühll (firstname.lastname@example.org)