Abstract. Over the last two decades, several methods have been developed to reduce subjectivity of geomorphosite selection through use of transparent assessment criteria. Most of these methods propose criteria such as integrity, rarity, representativeness and palaeogeographical importance for the evaluation of the «scientific value» of sites. For the assessment of their global quality, «additional values» of ecological, cultural, aesthetic and economic nature have, at times, been taken into consideration. This paper proposes a new assessment method that integrates both sets of values into the evaluation of geomorphosites. The method is described and its implementation in two different cases presented: compilation of an inventory of geomorphosites in the National Park of Adula (Ticino, Switzerland) and evaluation of the geocultural heritage of the Trient area (Valais, Switzerland).
In order to determine the spatial extension and the characteristics of permafrost within alpine talus slopes, two sites located in the western part of the Swiss Alps were studied using borehole drilling and electrical resistivity tomography (ERT) profiles. Three boreholes were drilled along an upslope-downslope transect in both talus slopes. In both sites, frozen sediments are present only in the two lowest boreholes, whereas the upper borehole does not present ice. This stratigraphy is confirmed by ground temperatures registered in the boreholes. In each site, three upslope-downslope ERT profiles were crossed with five, respectively four horizontal ERT profiles. All the upslope-downslope profiles show a difference in resistivities between the upper and lower parts of the slope, where a large resistive body with values higher than 35 kΩm is present. In the uppermost part of the profiles, the resistivities are lower than 10-15 kΩm. The borehole data allowed the stratigraphy obtained from the ERT inverted profiles to be validated, with regards to the distribution of frozen sediments as well as the depth of the detected structures. The results confirm that, in the two studied sites, permafrost is present in the lower sections of the talus slopes, whereas it is absent in the upper parts. Finally, the analysis of the talus structure showed that the permafrost stratigraphy, and in particular the ice content, may be an important element of interpretation of the palaeoclimatic significance of an alpine talus slope.
Surface temperature increases since the 1990s have often been associated with an increase in the speed of rock glaciers. Evidence of similar links on the centennial to millennial scale are, however, still lacking due to less focus to date on the medium-and long-term kinematics of these landforms. In order to assess (palaeo)climatic variations in rock glacier kinematics, we analysed the movements of the Stabbio di Largario rock glacier in the southern Swiss Alps using three different timescales. The Schmidt hammer exposure-age dating (SHD) was applied to study long-term kinematics in order to extrapolate the minimal age of the formation of the rock glacier, which may have started its development after the Mid-Holocene climate optimum, and to detect possible accelerations of the horizontal surface velocity during the Medieval Warm Period. Georeferentiation and orthorectification of six historical photographs of the rock glacier taken between AD 1910 and today were analysed using monoplotting to detect the rock glacier displacement on the decennial scale from the end of the Little Ice Age. Finally, differential global positioning system (dGPS) monitoring data available since AD 2009 were used to assess annual and seasonal creep rates of the rock glacier at present. Our results show a link between the periods of increase in mean air temperature on different timescales and variations in rock glacier kinematics and provide important new insights into rock glacier development and evolution on the long-term scale.
Abstract. The investigation and modelling of permafrost distribution, particularly in areas of discontinuous permafrost, is challenging due to spatial heterogeneity, remoteness of measurement sites and data scarcity. We have designed a strategy for standardizing different local data sets containing evidence of the presence or absence of permafrost into an inventory for the entire European Alps. With this brief communication, we present the structure and contents of this inventory. This collection of permafrost evidence not only highlights existing data and allows new analyses based on larger data sets, but also provides complementary information for an improved interpretation of monitoring results.
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