Swiss Permafrost Monitoring
The Swiss Permafrost Monitoring initiative PERMOS (http://www.permos.ch) maintains a network of 28 high alpine sites in order to document the state and changes of permafrost in Switzerland based on three main observation elements (ground temperatures, changes in subsurface ice and water content, and permafrost creep velocities). PERMOS is funded by the Federal Office for the Environment (FOEN), the Swiss GCOS Office at MeteoSwiss, and the Swiss Academy of Sciences (SCNAT).
The PERMOS Office (J. Noetzli) coordinates observation and reporting activities undertaken by the six partner institutions ETH Zurich (ETHZ, S.M. Springman, T. Buchli), the Universities of Fribourg (UNIFR, R. Delaloye, C. Hauck, C. Hilbich, M. Hoelzle, B. Staub), Lausanne (UNIL, C. Lambiel), Zurich (UZH, J. Noetzli, I. Gärtner-Roer, A. Vieli, A. Bast), the WSL Institute for Snow and Avalanche Research (SLF, M. Phillips, J. Noetzli) and the University of Applied Sciences and Arts of Southern Switzerland (SUPSI, C. Scapozza). A new 4-year contract period has started in 2015 for which the PERMOS Office has officially moved to the Department of Geosciences at the University of Fribourg and a second 50% position has been funded (B. Staub). A new 60 m borehole has been drilled in the Murtèl rock glacier on Corvatsch in the Upper Engiadine in order to secure the longest available temperature time series in mountain permafrost from the borehole drilled here in 1987, which is very likely to shear off in the next years. The project was funded by FOEN and carried by UZH.
Ongoing research projects and activities
Permafrost research activities at the Institute of Earth Sciences of the SUPSI University of Applied Sciences and Arts of Southern Switzerland (C. Scapozza, C. Ambrosi) continued after their beginning in 2013 with the affiliation to the PERMOS network. During this year research focused mainly on the assessment of rock glacier kinematics and ground surface temperatures. These local investigations were coupled with a regional climate analysis performed in collaboration with the University of Turin (S. Fratianni, E. Giaccone), for understanding the influence on permafrost conditions of the Southern Swiss Alps climate evolution. Within this framework, a research project based on Schmidt hammer exposure-age dating and historical analysis (Fig. 1) allows assessing the kinematics of the Splügenpass rock glacier in the last two millennia by comparison with climate evolution.
Figure 1. The Splügenpass rock glacier with the two historical mule tracks crossing its frontal part. The arched shape of the RP mule track is probably related to ground ice degradation between the Roman Period and the Late Middle Ages (Photo: C. Scapozza).
In parallel to its long-term monitoring of borehole temperatures and deformation in cooperation with PERMOS (J. Noetzli), the WSL Institute for Snow and Avalanche Research SLF investigated the impact of the snow cover on the thermal regime and stability of steep rock walls (A. Haberkorn, M. Phillips) with German project partners (D. Draebing, M. Krautblatter). Rock wall dynamics were monitored using terrestrial laserscanning and numerous rock slope failures were registered in the SLF rockfall database in the course of the summer 2015 heat wave - with information obtained via crowd sourcing (Fig. 2). The stability and thermal regime of high mountain infrastructure was monitored (M. Phillips) with various partners and record displacements of snow nets in the Matter valley which have been monitored since 1999 were registered. These displacements were confirmed by an in-situ GPS installed by the ETH Zurich (J. Beutel, S. Weber). A novel combination of time-lapse photography and terrestrial laser scanning is currently being applied to monitor the dynamics of the Ritigraben rock glacier (R. Kenner).
Figure 2. One of many rock fall events in the Swiss Alps during the summer 2015 heat wave: Spannort, September 2015 (Photograph Christian Schindler, Swiss Helicopter).
The Department of Geography at the University of Zurich (A. Vieli, A. Bast, I. Gärtner-Roer, J. Müller, S. Weber, V. Wirz) is announcing that part of the PERMOS monitoring program, a replacement 60 m borehole has been drilled and instrumented at Murtel rock glacier to continue the time series of the 1987 borehole. The PermaSense project has finished the new experiment setup to capture micro-seismic activity as an indicator for damage in steep bedrock permafrost. The continuous data get streamed in real time and is planned to be continued over the next year. Additional, initial datasets for repeat of terrestrial laser scanning, radar interferometry as well as drone-based orthophotos have been undertaken at Matterhorn and Dirru rockglacier in order to assess spatio-temporal changes.
The SNSF-Sinergia project «The evolution of Mountain Permafrost in Switzerland» (TEMPS, 2011-2015), which was led by the University of Fribourg and regrouping scientists from several institutions (ETH Zurich, Universities of Fribourg, Lausanne, and Zurich, SLF) finished in spring 2015. A particular aim of this project was combining observation and model-based research approaches to obtain an integrative view of the current state of mountain permafrost in the Swiss Alps and the governing processes for its recent and future evolution. A concluding TEMPS symposium (www.temps-symposium.ch) was held in the heart of Swiss mountains in Sion in February 2015 and was attended by more than 100 scientists and practitioners (Fig. 3).
Figure 3. Some of the TEMPS-Symposium participants took part to a ski touring 2-day excursion and visited in particular the Becs-de-Bosson/Réchy rock glacier.
Members of the Alpine Cryosphere and Geomorphology research group at the University of Fribourg, Department of Geosciences (C. Hauck, M. Hoelzle, R. Delaloye, N. Salzmann, C. Barboux, L. Braillard, C. Hilbich, A. Hasler, M. Kummert, S. Mari, A. Marmy, C. Mollaret, S. Nussbaumer, C. Pellet, B. Rick, P.-O. Schmid, B. Staub, J. Wicky) have deployed their activities on a wide range of topics including the analysis of rock mechanics and rock glacier dynamics (Fig. 4), sediment transport, geomorphology, geophysics, subsurface modelling and remote sensing related to permafrost essentially in the Alps, but also in other mountain regions over the world (e.g. Brooks Range – Alaska, Argentinean and Chilean Andes, Himalaya). A close collaboration has also been set up with ARPA (Regional Agency for Environment Protection) Aosta Valley in Italy. In 2015 Stefano Mari, Antoine Marmy and Benno Staub finished their PhDs on the regional pattern of rock glacier distribution and local hydrology, modelling of Alpine permafrost time series and integrative analysis of permafrost-related monitored data in the Swiss Alps, respectively.
Figure 4. 4-year time series of webcam images on the active eroding front of the 100 m wide Tsarmine rock glacier. As for many monitored sites in the Swiss Alps, the creep velocity of rock glaciers has dramatically increased over the last decades, and especially over the last years. The mean annual velocity of the Tsarmine rock glacier has for instance jumped from 1 to 4.5 m/year between 2011 and 2015. The availability of loose sediments downwards of the rock glacier front may be strongly enhanced. Survey activities are undertaken by the Universities of Fribourg and Lausanne with the support of the local community (Evolène) and regional services (Forest and Landscape Service, Canton of Valais).
At the University of Lausanne, the current main activities of the small group formed by C. Lambiel, J.-B. Bosson, N. Deluigi and Master students focus on permafrost mapping and modelling and ground ice related movements. The repartition of subsurface ice was investigated in post LIA proglacial margins located in permafrost environment and on solifluction slopes. These data are used as input variables for predicting the occurrence of mountain permafrost with machine learning algorithms. Within this project, three different algorithms were tested this year: Artificial neural networks (ANN), Support Vector Machines (SVM) and Random Forest (RF). They have demonstrated to be efficient for permafrost distribution modelling with consistent results compared to the field reality. A new project started on mountain solifluction with the aim of understanding the factors controlling the process activity and of investigating the role of permafrost in the movements. More generally, studies have continued on the decadal and current evolution of rock glaciers with digital photogrammetry, Lidar and GPS surveys, as well as the use of automatic cameras. Schmidt Hammer was used on rock glaciers to obtain surface exposure age data with the aim of reconstructing the past activity of rock glaciers. Finally, a funding was obtained from the Swiss National Foundation (SNF) for an interdisciplinary project called „Integrating spatial predictions of vegetation, soils, geomorphology and hydrology for improved assessment of ecosystem services under climate change“ (INTEGRALP). The project will investigate the influence of permafrost conditions on the vegetation. Many of the data collected in monitoring projects carried out by the University of Lausanne (Fig. 5) (borehole and surface temperatures, rock glacier velocities, electrical resistivities) are integrated in the PERMOS network.
Figure 5. Location of the new Mont Fort borehole, 3300 m a.s.l. (Swiss Alps). The borehole was drilled in October 2014. Temperatures at 20 m are -2°C. (Photo: Christophe Lambiel, University of Lausanne)
Report prepared by Reynald Delaloye ([email protected])