February 6, 2021
Rio Frio Glacier (RF) in 1990 and 2020 Landsat images. Red arrow 1990 terminus, yellow arrow 2020 terminus, orange arrow new lakes formed after 2000, purple dots snow line.
The “Rio Frio” Glacier is at the headwaters of the Rio Frio a tributary to Rio Palena in Parque Nacionale Corcovado of Palena Province of Chile. Davies and Glasser (2012) noted that overall glaciers in the region lost 14% of their area from 1986 to 2011. Paul and Molg (2014) assessed changes of glaciers in the Palena district, Chile revealing a total area loss of 25% from 1985 to 2011. Area loss below 1000m elevation was 50–100% and the number of proglacial lakes increased from 223 to 327. Carrivick et al (2016) reported the glaciers in the region had an average thickness of 41 m, this is relatively thin allowing for the rapid area loss. Here we examine glacier change from 1990 to 2020 using Landsat imagery.
The Rio Frio Glacier terminated in a proglacial lake in 1990 at 720 m and the snowline is at 1100 m. The next glacier to the south has two arms terminating at 900 m with no proglacial lakes at the terminus see orange arrows. In 2000 there is limited retreat and Rio Frio Glacier still terminates in the lake, and the snowline is at 1150 m. At the next glaciers south there is no proglacial lakes evident at the terminus. By 2019 Rio Frio Glacier has retreated from the lake and the snow line is at 1100 m at the start of February. The next glacier south two new proglacial lakes have developed at orange arrows. By 2020 the glacier terminus has retreated 500 m to an elevation of ~880 m. Rio Frio glacier has lost more than 50% of its area below 1000 m. The glacier still has maintained an accumulation zone each year indicating that without further warming it can survive. The next glacier south has retreated exposing two new proglacial lakes that now are no longer reached by the glacier.
The large scale loss of these two glaciers is typical for the region as noted by the references above and by the examples of Tic Toc Glacier, Erasmo Glacier and Hornopiren Glacier. In this case the two new proglacial lakes are small and no longer in contact with the glacier, result they pose little glacier outburst flood risk. The lake beyond the terminus of Rio Frio Glacier has neither adjacent significant steep slopes or ice in contact and poses little risk as well.
Rio Frio Glacier in 2000 and 2019 Landsat images. Red arrow 1990 terminus, yellow arrow 2020 terminus, orange arrow new lakes formed after 2000, purple dots snow line.