April 20, 2018
Changes in four glacier at the headwaters of Rio Tigre, Argentina in 1987 and 2017 Landsat images. The red arrow indicate the 1987 terminus position and the yellow arrow the 2017 terminus position.
Glaciers form the headwaters for Lago Cholila which drains into Futaleufu River in west central Argentina . Davies and Glasser (2012) mapped the glaciers in the Hornopiren region just to the northwest and Parque Nacionale
Corcovado just to the southwest finding a 13-15 % area loss from 1986 to 2011. Here we examine the changes of four of the glaciers in Landsat images from 1987-2017.
In 1987 only one of the four glaciers terminates in a lake #1, #2, and #3 end at the far end of a cirque basin and #4 terminates at the downvalley end of a basin. Glacier #3 also has a 400 m wide connection from the upper to the lower glacier, pink arrow. By 2000 a small terminus lake has appeared at #2 and #4, while #1 has retreated around a bend in the lake. In 2016 the upper and lower portion of #3 have nearly separated, pink arrow. No lake has yet formed. By 2017 #1 has retreated 700 m since 1987, with the remaining glacier only 1400 m long. Glacier #2 has retreated 500 m with a new lake of the same width having developed. Glacier #3 thinning instead of retreat has dominated. The glacier will continue to lose its terminus tongue, with the lower glacier effectively cutoff from the upper glacier. Glacier #4 has retreated 600 m, with a new lake having formed, and the terminus now having retreated upglacier of the lake. The headwaters of the Lago Cholila has and is losing significant glacier volume, which is leading to new and expanding lakes. Below a Google Earth image indicate the new lake and the limited accumulation zone on Glacier #4. The retreat is similar to that we reported for the Sierra de Sangra to the south and Pico Alto just to the north in Chile.
Changes in four glacier at the headwaters of Rio Tigre, Argentina in 2000 and 2016 Landsat images. The red arrow indicate the 1987 terminus position and the yellow arrow the 2017 terminus position.
Google Earth image indicating new lake formed by retreat of Glacier #4.