Climate change and cryosphere in high mountains: updates from the Capanna Margherita hut study case (Punta Gnifetti, Monte Rosa Massif, Pennine Alps)

Mountain glaciers and permafrost are among the most evident geomorphological tracers of climate change. In the last decades, they showed a growing and faster response also at very high elevations, leading to increased instability of the Alpine landscape. In the meanwhile, they became of great interest also for their possible interactions with human activities and infrastuctures.

On the highest massif of the Alps, as for example the Monte Rosa, this interaction is mainly represent by the one with mountaineering activities. The top of Gnifetti Peak (4554 m a.s.l.), with the Capanna Margherita hut (the highest in Europe), is under investigation to better understand the effects of global warming on hut stability and mountaineering routes safety. Thanks to the cooperation between the Italian Alpine Club (CAI), University of Turin (UniTo), Politecnico di Milano (PoliMi) and IMAGEO srl, a first assessment of geological and glacial settings of hut surroundings have been performed on 2019. Data collection continued on 2020, by means of comparative analyses designated to: a) identify the relevant geomechanical features for rock mass stability; b) verify permafrost related instabilities; c) reconstruct the ice-covered morphology of the Punta Gnifetti peak; d) calculate rock-building interactions. Here below the related results:

1) A 3D model of the area has been obtained by integrating helicopter-borne photogrammetry with terrestrial laser scanner surveys.

2) Glacier thickness at the Colle Gnifetti has been established thanks to GPR survey.

3) From the comparison of a large number of historical pictures a first multi-temporal stability analysis highlighted sector of greater instability. Results of this work are freely available on the website www.geositlab.unito.it/capanna .

4) The geomechanical features of the rock mass below and around the hut have been retrieved from the analysis of the dense point cloud provided by terrestrial laser scanner integrated with direct field investigations.

5) Constructive drawing of the hut have been obtained from the terrestrial laser scanner point cloud integrated with manual measurements taken inside the structure.

6) 3D numerical modelling are going to be applied in order to simulate the interactions between the hut and the foundation rock on the base of the above data.

The ongoing activities are addressed to a detailed study of more vulnerable sectors of the Punta Gnifetti to better understand morphodynamics and possible interactions with mountaineering activities. This will be performed through a two-way investigation. On one hand, a link with alpine guides and mountain hut keepers has been established, in order to have “sentries” ready to report instabilities and detect new hazards and risks. On the other hand, a monitoring network will be installed around Capanna Margherita in order to collect data on weather, glacier and permafrost conditions.