Infrasound analysis of break-off events  from Planpincieux glacier, Mount Blanc, Italy

Glacier break-off events constitute a severe hazard in Alpine regions and their effects are expected to increase soon because of climate changes. Within this rapidly changing scenario, the development and implementation of new monitoring solutions and warning systems, able to detect collapses and possibly estimate the volumes, is of critical importance. In this paper we present the analysis of avalanching activity from Planpincieux glacier (Aosta valley) through infrasound data collected by a small aperture (~ 150 m) array deployed at short distance (~ 2000 m) from the hanging front. The analysis is performed over five time periods between August 2020 and December 2022 summing up into 360 days. From a data set of confirmed events, infrasound wave parameters (intensity, peak amplitude, frequency and duration) are compared with collapse volumes estimated from photogrammetry and experimental relations are defined. Morerover, characteristics of infrasound signals of confirmed events are used to extract signals that are likely produced by collapses from the whole dataset of infrasound detections and a volumetric flux of collapses from the front of the Planpincieux glacier is derived through time.