The southern slope of the Mont Blanc massif in the Aosta Valley, Western Alps, is predominantly composed of fractured granitic rocks. This geological configuration, combined with the presence of sub-vertical rock walls exceeding 4.000 meters in height, makes this area susceptible to rockfalls or ice-rock avalanches of significant importance. The Brenva Glacier area is particularly relevant in this regard as it has experienced two ice-avalanches in the last century, with the most significant occurring in 1997. Recent geo-structural studies demonstrate that small-to-medium-sized rockfalls in this area are common and suggest that events of the magnitude of the 1997 collapse may occur relatively infrequently, while events with volumes of tens of thousands of cubic meters could happen annually. In such conditions, it is important to continue and reinforce monitoring and early-warning activities to mitigate the potential risk posed by ice-rock avalanches.

For these reasons, two periodic monitoring campaigns with the GBInSAR LiSAmobile system were carried out in 2017 and 2020.

This site is challenging due to the unique environmental and logistical conditions that were faced. The LiSAmobile system was installed on an exposed rock spur of the glacier at an altitude of 3.200 meters above sea level, and a hybrid power system was required to function effectively at those altitudes and with average temperatures close to or below 0°C.