Increased mass loss of glaciers in Volcán Domuyo (Argentinian Andes) between 1962 and 2020, revealed by aerial, ASTER and Pléiades stereo imagery

DANIEL FALASCHI; JOAQUÍN BELART; CLAUDIO BRAVO; ETIENNE BERTHIER; MARIANO CASTRO

Zurich

Conferencia; International Association of Cryospheric Sciences. Regional Assessments of Glacier Mass Change (RAGMAC) 2020-2023; 2021

World Glacier Monitoring Service

We assessed the 1968-2020 geodetic mass balance of glaciers (~23 km2) in Volcán Domuyo in NorthernPatagonia by differencing Digital Elevation Models (DEMs), derived from historical aerial photographs(1962 and 1984), ASTER (2003) and Pleiades (2012 and 2020) stereo images. Overall, results showed aslight mass loss of -0.15 ±0.09 m w.e. a-1 between 1962 and 2020 (Figure 1), with a peak in negativeconditions (-0.99 ±0.19 m w.e. a-1 ) between 2012 and 2020 Figure 2).Methodologically, the generation of the 1962 DEM posed the greatest challenge. The usage of contactprints of the frame stereo imagery scanned in a non-photogrammetric device, instead of originalnegative films (unavailable) scanned in a proper photogrammetric unit, introduces non-linear errors inthe derived dh/dt grids. To account for these limitations, the 1962 DEM was cropped around eachglacier unit with a 1 km buffer, adding a fifth-degree polynomial fit fromthe stable areas in the buffer to the coregistration procedure.This study provides a long-term mass balance assessment for a regionwhere glaciological studies are sparce, making extensive use of mostlyhigh-resolution data.