Cross-analysis of temperature and slope microseismic activity for the Matterhorn peak study site (North-Western Alps)

A microseismic and a thermometric monitoring systems were installed, in the framework of the Interreg IIIA Alcotra “PERMAdataROC” project, on the Italian side of the Matterhorn peak, close to the J.A. Carrel hut. The analysis of a one year temperature recording has evidenced the influence of the slope exposure (north vs. south) on data recorded during different periods of the year and at different depths. In particular, given the Matterhorn peak geometry, approximately a pyramid, it emerges that the thermal gradient north/south and surface/depth can make possible an increase in stress concentration on weakness surfaces that pass through the rock mass and promotes instability events. The numerical correlation between a 6-months microseismic dataset and thermal data has evidenced a temporal concentration of the microseismic activity when temperature falls rapidly. While, no particular activity emerges when temperature raises. Integration of the microseismic monitoring with a thermometric system can then contribute in investigating rock response to climate forcing. Once fully developed and tested, this technique could become a helpful tool for warning in advance when climatic conditions that can favour a rock slope instability set up.