Glacier thickness modelling and monitoring with geophysical data constraints: A case study on the Indren Glacier (NW Italy)

The ongoing global temperature increase has accelerated the mass loss of glaciers worldwide, with Italian alpine glaciers being particularly vulnerable due to their small size, complex geometries and exposition that implies a fast reaction to thermal and hydrological modifications. In such a frame, the Indren Glacier (Aosta Valley, north-western Italian Alps) provides a valid test site to check the thickness evolution over the last two decades (1999–2020), through an integrated approach combining historical data, on-site geophysical measurements, remote sensing surveys, modelling and temperature analysis. Using a 2018 helicopter-based photogrammetric survey and Ground Penetrating Radar (GPR) survey campaigns of 2020, we obtained new input data and constraints to build up an updated thickness model for the whole glacier through the Glacier Thickness Estimation algorithm (GlaTE). Ice thickness is indeed a key parameter to estimate the ice volume and use it as further input in evolutionary models forecasting future scenarios. As a part of this integrated approach, we also analysed remote sensing and temperature data, finding a major modification in the glacier conditions over the last decade. Further comparing these results with previous studies, we identified a significant decrease in ice thickness, and we confirmed the presence of an over-deepening in the glacier central widest part. This integrated methodology enhances our understanding of glacier dynamics and improves predictions of future changes, offering crucial insights for managing water resources and mitigating natural hazards in the alpine region.