Recent mass-balance changes of Agua Negra glacier (30°S) in the Desert Andes of Argentina

PITTE, PIERRE; MASIOKAS, MARIANO; GARGANTINI, HERNÁN; RUIZ, LUCAS; BERTHIER, ETIENNE; FERRI HIDALGO, LIDIA; ZALAZAR, LAURA; DUSSAILLANT, INÉS; VIALE, MAXIMILIANO; ZORZUT, VALENTINA; CORVALÁN, ERNESTO; SCARPA, JUAN PABLO; COSTA, GUSTAVO; VILLALBA, RICARDO

JOURNAL OF GLACIOLOGY

INT GLACIOL SOC

Año: 2022 p. 1 - 13

0022-1430

The Desert Andes contain >4500 ice masses, but only a handful are currently being monitored. Wepresent the mass changes of the small mountain glacier Agua Negra (1 km2) and of the rest of glaciersin the Jáchal river basin. Remote-sensing data show Agua Negra glacier lost 23% of its area during1959–2019. Glaciological measurements during 2014–2021 indicate an average annual mass balance of −0.52 mw.e. a−1, with mean winter and summer balances of 0.80 and −1.33mw.e. a−1,respectively. The Equilibrium Line Altitude (ELA) is estimated to be 5100 ± 100m a.s.l., whichcorresponds to an Accumulation Area Ratio (AAR) of 0.28 ± 0.21. Geodetic data from SRTMX and Pléiades show a doubling of the loss rate from −0.32 ± 0.03mw.e. a−1 in 2000–2013, to−0.66 ± 0.06mw.e. a−1 in 2013–2019. Comparatively, the ice losses for the entire Jáchal riverbasin (25 500 km2) derived from ASTER show less negative values, −0.11 ± 16mw.e. a−1 for2000–2012 and −0.23 ± 14mw.e. a−1 for 2012–2018. The regional warming trend since 1979and a recent decline in snow accumulation are probably driving the observed glacier mass balance.