February 18, 2022
Palomo Glacier, Chile in Landsat 5, 8 and 9 images illustrating retreat from 1987 position, red arrow, and expansion of bare rock areas amidst the glacier at Point A,B and C. Note lack of retained snowcover in 2022.
Palomo Glacier is a large valley glacier in Central Andes of Chile. Adjacent to the Cortaderal Glacier and Universidad Glacier, it flows east from Volcan Paloma (4860 m) and drains into the Rio Cortaderal. Rio Cortaderal is in the Cachapoal River watershed that supplies two Pacific Hydro projects; a 110 MW run of river project at Chacayes and the 78 MW Coya run of river project a short distance downstream. The glacier is an important water resource from December-March. Bravo et al (2017) quantified this resource for nearby Universidad Glacier that supplied 10-13% of all runoff to the Tinguirica Basin during the melt season. La Quesne et al (2009) reported that Palomo Glacier retreated 1160 m from 1955-1978 and advaned ~50 m from 450 m 1987-2007. They reported that Palomo Glacier had an equilibrium balance durng the 1987-2000 period, which drove the lack of retreat. Here we examine the changes of this glacier from 1987-2022 using Landsat 5, 7, 8 and 9 images, and the unusually high snow lines during the winter of 2022 due largely to a January heat wave (Washington Post, 2022). This is the first post using Landsat 9, that extends this invaluable data record.
In 1987 Palomo Glacier terminus had been in slight advance over the previous decade. The area of bare rock at Point A was 0.25 km2. At Point B and C limited exposed rock was evident on two rock ribs. The snowline is below Point A at 3300 m. By 2002 there is minor retreat and the area of exposed rock at Point A has expanded, with the snowline at 3600 m. By 2015 the terminus has retreated 700 m to the north end of steep slope on the east margin of the glacier. The exposed bedrock area at Point A is now 1 km2. the snowline is at 3800 m. By mid-January 2022 the glacier has only ~10% snowcover remaining, mostly above 4000 m. Retreat since 1987 is now ~1200 m. The bedrock area at Point A is 1.5 km2. Point B is expanding ridge of bedrock and the rib or rock at Point C now separates the glacier from flow on the south facing slope east of Point C.
By February 8, 2022 with six weeks left in the melt season there is no evident retained snowpack. This will accelerate both retreat, thinning and area loss of this glacier. This story is playing out at glaciers across the region such at Olivares Glacier, Chile, Cortaderal Glacier, Chile and Volcan Overo, Argentina
Palomo Glacier, Chile in Landsat 7 and 9 images illustrating retreat from 1987 position, red arrow, and expansion of bare rock areas amidst the glacier at Point A,B and C.