P. Pogliotti

Monitoring Rock Wall Temperatures and Microseismic Activity for Slope Stability Investigation at J.A. Carrel Hut, Matterhorn

Recent climate changes are increasing the frequency of rock-slope instabilities in the Alpine region. The formation of cracks leading to rockfalls causes a release of energy propagating in form of elastic waves. These latter can be detected by a suitable transducer array together with the vibrations generated by the impact of rockfalls. Geophones are among the most effective monitoring devices to investigate both these phenomena. A monitoring system composed by geophones and thermometers was installed at the J.A. Carrel hut (3829 m a.s.l., Matterhorn, NW Alps) in the framework of the Interreg Alcotra projects PERMAdataROC and MASSA by CNR IRPI and ARPA with the financial and logistic support of the Valle d’Aosta Region. The correlation between temperature trends and microseismic events is presented: cold periods characterized by a rapid temperature decrease present higher concentration of microseismic activity. However, not every drop in temperature is associated to microseismic activity, and the identification of the processes generating microseismic events in occasion of rapid temperature decrease is still uncertain. The objective of the ongoing research activity is to analyze in deep the statistical correlation between the number of microseismic records and the temperatures of air and rock in order to investigate the existence of recurrent patterns in the detected signals.

Analysis of Factors Controlling Landslide Susceptibility in the Aosta Valley (NW Italy): Relationship to Climatic and Environmental Changes

Recent climate changes are evident, especially in alpine environments, and have implications for natural hazards. Geomorphological studies have been performed at a regional scale in the Aosta Valley to better understand the spatial distribution and frequency of landslides and to investigate their controlling factors. A comparison between areas with permafrost and the rest of the territory has also carried out. Landslides inventories, permafrost distribution and geothematic maps have been produced and integrated into a GIS system. The lowest values of landslides density have been observed within the permafrost areas with respect to the whole region. The frequency of landslides has increased slightly during the last few decades in high mountains areas, possibly due to climate warming.