Glaciers in the Andes are among the fastest shrinking and largest contributors to sea level rise in the world. They also represent crucial water resources in many tropical and semi-arid portions of this extensive mountain range. Yet, the magnitude of the recent ice loss over the entire Andes cordillera is still debated. Here we present Andean glacier mass changes (from 10°N to 56°S) between 2000 and 2018 using time series of digital elevation models derived from ASTER stereo images. The total mass change is -22.9 ± 5.9 Gt yr-1 (-0.72 ± 0.22 m w.e. yr-1), with the most negative mass balances in the Patagonic Andes (-0.78 ± 0.25 m w.e. yr-1) and the Tropical Andes (-0.42 ± 0.24 m w.e. yr-1), and relatively moderate losses (-0.28 ± 0.18 m w.e. yr-1) in the Dry Andes. Sub-period analysis (2000-2009 vs. 2009-2018) reveals steady mass loss in the Tropics and south of 45°S. Conversely, a shift from slightly positive to strongly negative mass balance is measured between 26° and 45°S. In this latter region, the rapid glacier loss in recent years coincides with extremely dry conditions since 2010 and partially helped to mitigate the negative hydrological impacts of this severe drought. These results provide a comprehensive, high resolution and multi-decadal dataset of recent Andes-wide glacier mass changes that constitutes a relevant basis for calibration and validation of hydrological and glaciological models intended to project future glacier changes and their hydrological impacts.

Supplement to: Dussaillant, Ines; Berthier, Etienne; Brun, Fanny; Masiokas, Mariano; Hugonnet, Romain; Favier, Vincent; Rabatel, Antoine; Pitte, Pierre; Ruiz, Lucas (2019): Two decades of glacier mass loss along the Andes. Nature Geoscience, 12(10), 802-808