Articles | Volume 11, issue 1
Research article
24 Feb 2017
Research article |  | 24 Feb 2017

Recent geodetic mass balance of Monte Tronador glaciers, northern Patagonian Andes

Lucas Ruiz, Etienne Berthier, Maximiliano Viale, Pierre Pitte, and Mariano H. Masiokas

Abstract. Glaciers in the northern Patagonian Andes (35–46° S) have shown a dramatic decline in area in the last decades. However, little is known about glacier mass balance changes in this region. This study presents a geodetic mass balance estimate of Monte Tronador (41.15° S; 71.88° W) glaciers by comparing a Pléiades digital elevation model (DEM) acquired in 2012 with the Shuttle Radar Topography Mission (SRTM) X-band DEM acquired in 2000. We find a slightly negative Monte-Tronador-wide mass budget of −0.17 m w.e. a−1 (ranging from −0.54 to 0.14 m w.e. a−1 for individual glaciers) and a slightly negative trend in glacier extent (−0.16 % a−1) over the 2000–2012 period. With a few exceptions, debris-covered valley glaciers that descend below a bedrock cliff are losing mass at higher rates, while mountain glaciers with termini located above this cliff are closer to mass equilibrium. Climate variations over the last decades show a notable increase in warm season temperatures in the late 1970s but limited warming afterwards. These warmer conditions combined with an overall drying trend may explain the moderate ice mass loss observed at Monte Tronador. The almost balanced mass budget of mountain glaciers suggests that they are probably approaching a dynamic equilibrium with current (post-1977) climate, whereas the valley glaciers tongues will continue to retreat. The slightly negative overall mass budget of Monte Tronador glaciers contrasts with the highly negative mass balance estimates observed in the Patagonian ice fields further south.

Short summary
Our paper assesses the glacier mass change in the northern Patagonian Andes of Argentina and Chile, which is crucial to understanding how climate change is affecting them. We have found that between 2000 and 2012, glaciers in this region were slightly out of balance, with larger valley glaciers losing more mass than smaller mountain glaciers. The slightly negative mass balance of the northern Patagonian Andes contrasts with the highly negative mass balance of the Patagonian ice fields.