Report from July 1990

The main activity of the group which now consists of about 30 members concentrated on the discussion of the first analyses from the permafrost cores recovered by drilling through the Frozen Ground active rock glacier Murtel/Corvatsch in 1987. A corresponding national workshop took place at VAWIETH, Zurich, on 24 February 1989, during which the results of the pilot analyses were presented and discussed together with preliminary results from other studies (borehole measurements, thermal analyses, flow considerations) of the interdisciplinary project. The reason for carrying out such pilot analyses was the simple but remarkable fact that Alpine permafrost constitutes a so far unaccessible and therefore still completely unknown "archive" of information. A summary of the presentations and discussions is now being published in order to document the state of understanding to coordinate further work.

Research projects of various institutes continue on permafrost and rock glacier mapping (Valaise, Grisons), borchole and core studies (rock glacier Murtel/Corvatsch), hydrology of mountain permafrost (Valais), permafrost/snow-interactions and avalanche protection in Alpine permafrost (Grisons), and photogrammetric long-term monitoring of selected rock glaciers (Valais, Grisons). Current engineering problems to permafrost in the Swiss Alps concern foundations of avalanche protection work, dams for protection against rock falls, stability of galleries for ski runs in creeping rocks and foundations for cable car construction. A major study on periglacial debris flows from the catastrophic 1987 storm events is now reaching completion and steps are being undertaken to establish a long-term monitoring program on the thermal and mechanical stability of Alpine permafrost in view of possible future warming trends.

The Swiss Coordinating Group on Permafrost will be responsible for the organization of the 1991 International Workshop in Interlaken of the IPA Working Groups on Mountain Permafrost and on Periglacial Environments.

Report from December 1990

First analysis of core samples from the uppermost 20 metres (shallow core) ofthe active rock glacier Murtal indicate that the permafrost contains considerable refrozen water from the earlier part of the Holocene time period and which formed from an open reservoir without contamination by modern (20th-century) water. Analyses concerning ice fabrics, isotopes ( 3H and stable isotopes), chemistry (major anions and cations, dissolved gases, particulate anthropogenic species), mineralogy, pollen and gas content ( 3He, noble gases) are now being extended to greater depth. The highest-perhaps even late glacial-ages are expected at the base of the main shear zone at about 30 m depth. The blocky layer from 30 to 50 m depth may have a completely different origin than the massive near-surface ice studied so far. Material from the shallow core is still available for further tests and pilot studies, whereas the deep core must be saved for well defined studies at the most important and most appropriate depth intervals. Published results and more detailed information on availability of core material can be obtained from VAW/ETH Zürich.

A workshop was held at ETH Zürich on Alpine snow, ice and water in a wanning atmosphere with contributions about climatic scenarios and the enhanced greenhouse effect (Siegenthaler, Berne): energy exchange between the atmosphere and snow/ice surfaces (Fihn, Weissfluhjoch/Davos); glaciers (Patzelt, Innsbruck and Aellen, Zürich); permafrost (Haeberli, Zürich): periglacial debris flows (Zimmerman, Zürich); and runoff (Schindler, Berne). As a consequence of atmospheric warming during the first half of the 20th century, the lower boundary of Alpine permafrost distribution probably shifted in altitude, causing local degradation of underground ice and destabilization of formerly frozen slopes. Continued or even accelerated warming is likely to induce further retreat and degradation of permafrost in the Alps. The evolution of the
coming years and decades should be documented with an appropriate monitoring programme (high-precision photogrammetry, borehole measurements, data bank containing results of geophysical soundings).