Queulat Glacer Complex, Chile Recession 1987-2021

Seven outlet glaciers of the Queulat glacier complex, Chile in 1987 and 2020 Landsat images. A=Rosselot Glacier and D=Colgante Hanging Glacier are the only ones in 1987 not terminating in a proglacial lake. The other five retreated from a proglacial lake since 1987 and Rosselot Glacier retreat has led to formation of two lakes. 

Nevado Queulat, Chile is the centerpiece of the Queulat National Park in the Aysen Region.  This massif is host to the Queulat glacier complex, which has a number of outlet glaciers. Rosselot Glacier is the largest glacier and it flows north draining into Lago Rosselot and then the Rio Palena. Colgante Hanging Glacier flows south and is the second largest terminating at the top of a cliff  as a hanging terminus creating a spectacular waterfall.  Paul and Molg (2014) observed a rapid retreat in general of 25% total area lost from glaciers in the Palena district of northern Patagonia from 1985-2011. Meier et al (2018) note a 48% reduction in glacier area in the Cerro Erasmo and Cerro Hudson region, since 1870 with half of that occurring since 1986. The 3.8 km retreat of Erasmo Glacier from 1998 to 2018 is a rate of ~200 m/year.   Here we examined the changes from 1987 to 2021 of seven outlet glacier locations around the ice cap.

Seven outlet glaciers of the Queulat glacier complex in Queulat National Park in Chile in 2021 Sentinel 2 image. A=Rosselot Glacier and D=Colgante Hanging Glacier are the only ones in 1987 not terminating in a proglacial lake. The other five retreated from the proglacial lake since 1987 and Rosselot Glacier retreat has led to formation of two lakes. 

In 1987 Rosselot (A) terminates against the valley where the valley turns to the east,and there is no lake at the terminus.  In 1999 glacier retreat has exposed a new lake that is 900 m across.  By 2015 the glacier has retreated south of a second lake that is 700 m across.  In 2021 the glacier has retreated 250 m from the edge of the lake terminating at an elevation of 650 m. The total retreat from 1987-2021 has been 2100 m, ~60 m per year.  This is the loss of  15% of the entire glacier length.

Seven outlet glaciers of the Queulat glacier complex, Chile in 1999 and 2015 Landsat images.

Outlet Glacier B terminates in a lake at 750 m.  In 1999 the glacier has retreated to the top of a steep slope above the lake terminating at 850 m.  In 2015 the glacier is terminating at 925 m and is receding up a north-south oriented valley. By 2021 the glacier has retreated 1100 m from the shore of the lake.

Outlet Glacier C terminates in a small fringing proglacial lake.  By 1999 the glacier has retreated ~400 m to the base of a steeper slope, there is still ice cored moraine beyond the terminus. By 2015 a 500 m lake has formed beyond the terminus.  In 2021 the glacier has retreated ~1000 m since 1987.

Colgante Hanging Glacier (D) terminates at the top of a steep cliff in 1987.  The glacier reamins at the top of this cliff up to 2021, with considerable avalanching off the front into the valley below.  A reconstituted glacier at the bottom of the cliff is thinning.

Outlet Glacier (E) terminated in a proglacial lake  at 700 m elevation in 1987.  By 1999 the glacier had a tenuous connection to the lake with a reconstituted stagnant area in contact with the lake. In 2015 the glacier no longer reaches the lake. In 2021 the terminus of the glacier is 400 m from the lake.

Outlet Glacier (F) terminated in a proglacial lake at 750 m elevation in 1987.  In 1999 the glacier still connected to the lake. By 2015 the glacier had receded from this lake. In 2021 the glacier has retreated 350 m from the lake and terminates at  1000 m.

Outlet Glacier G is a stagnant debris covered glacier tongue that is in contact with a proglacial lake in 1987 and 1999.  By 2015 the glacier has retreated from contact with the lake.  In 2021 the glacier has retreated 600 m across an outwash plain from the lake.

Barcaza et al (2017) indicate that Colgante Hanging Glacier did not retreat from 2000-2015, while Rosselot Glacier lost 0.9 km2.

Queulat Norte Glacier, Chile Retreat Creates Two Lakes

 Queulat Norte Glacier in 1987, 2000 and 2016 Landsat images indicating retreat from 1987 (red arrow) to 2016 (yellow arrow). Green arrow indicates former tributary, orange arrow area of  new bedrock exposure and pink arrow expanding medial moraine. Two new lakes have formed due to the 1950 m retreat. 

Nevado Queulat, Chile is the centerpiece of the Queulat National Park in the Aysen Region.  The largest glacier draining the substantial ice cap on this mountain flows north draining into Lago Rosselot and then the Rio Palena.  Here we examine 1987 to 2016 Landsat imagery to identify changes in this glacier.    Paul and Molg (2014) observed a rapid retreat in general of 25% total area lost from glaciers in the Palena district of northern Patagonia from 1985-2011.

In 1987 the glacier terminates against the valley where the valley turns to the east, red arrow.  There is no lake at the terminus. The tributary at the green arrow connects to the main glacier.  There is no evident medial moraine at pink arrow.  There is no exposed bedrock in the accumulation zone at orange arrow.  In 2000 glacier retreat has exposed a new lake that is 900 m across.  The tributary at the green arrow is no longer connected.  A medial moraine s evident at the pink arrow and bedrock is exposed at orange arrow. By 2016 the glacier has retreated south of a second lake that is 700 m across.  Total retreat from 1987-2016 has been 1950 m, 65 m per year.  This is the loss of  15% of the entire glacier length.  The medial moraine has expanded up and downglacier indicating greater melting and an upward shift of the snowline.  The area at the orange arrow is a significant band of bedrock, indicating that this is no longer an accumulation zone. This bedrock is at 1700 m, the current terminus is at 600 m and the top of the glacier is at 2000 m, leaving only a 300 m elevation band in the accumulation zone. Examination of the region just above the terminus indicates significant ablation hollows/depressions indicative of stagnant ice, green arrows.  There is also an area of debris from a subglacial stream emerging at the surface yellow arrow. The retreat is as significant as that of Erasmo Glacier as a percentage of glacier size.

 

2016 Google Earth image of Queulat Norte Glacier indicating retreat from 1987 (red arrow) to 2016 (yellow arrow). Green arrow indicates former tributary, orange arrow area of  new bedrock exposure and blue arrows indicating flow. 

Stagnant nature of the lower glacier in 2016 with ablation hollows/depressions at green arrows and yellow arrow indicating sub-glacial stream that emerges at surface and deposits debris.