Unveiling the role of the bedrock topography on glacier evolution in Patagonia

The Southern Patagonian Icefield has been observed to exhibit one of the highest mass loss rates globally. However, the individual glaciers within this icefield show significant variations in their contributions to these loss rates, both in terms of space and time. This phenomenon is particularly evident in the glaciers Perito Moreno, Viedma, and Upsala, the latter being the largest glaciers in Argentina with its adjacent basins. Since the climatic sensitivity of lake-terminating glaciers can be strongly influenced by the bedrock topography, we surveyed these three glaciers for the first time with a 25 MHz helicopter-borne radio-echo sounding system.  The data was then incorporated into an state-of-the-art reconstruction approach to derive basin-wide ice thickness information and, subsequently, information regarding the subglacial bedrock topography. This enables the investigation of the potential of future glacier retreat due to the role of buoyancy-driven glacier calving. Furthermore, we analyzed the elevation changes from 2000 to 2024 based on SRTM and TanDEM-X microwave satellite data, the surface velocity evolution of these glaciers, and incorporated bathymetric measurements.