January 28, 2019

Turbio Glacier Retreat, Argentina Generates New Lake

Posted by Mauri Pelto

Turbio Glacier retreat from 1986 to 2018 in Landsat images.  Red arrow is 1986 terminus location, yellow arrow 2018 terminus location and pink arrow glacier across the border in Chile.

Turbio Glacier is at the headwaters of the Turbio River, Argentina and flows into Lago Puelo.  The glacier descends east from  Chile/Argentina border at 1500 m descending into a low slope valley at 1300-1000 m.  From 1986-2018 this glacier like many others nearby has retreated substantially leading to development of a new lake.  Wilson et al (2018) noted a substantial growth in the number of lakes in the central and Patagonian Andes due to the ongoing rapid retreat.  Masiokas et al (2008) reported that significant warming and decreasing precipitation over the 1912–2002 interval in the region. Harrison et al (2018) observed the number of glacier lake outburst floods have declined despite the increase in lakes.

In 1986 the glacier terminated at the southeast end of a buttress at the junction with another valley, red arrow. The glacier was 4.3 km long and was connected to a headwall segment that extends to 1500 m. There is no evidence of a lake at the terminus of Turbio Glacier.  Across the divide in Chile the glacier with a pink arrow has a length of 3 km.  In 1998 the retreat from 1986 has been modest and no lake has formed at Turbio.  Across the border in Chile the glacier has divided into two sections.  By 2017 Turbio Glacier has retreated exposing a new lake.  The glacier is essentially devoid of retained snowpack illustrating the lack of  a significant accumulation zone that can sustain it.  Across the border in Chile the glacier has nearly disappeared with the lower section revealing a new lake and little retained snowpack indicating it cannot survive.  By 2018 Turbio Glacier has retreated 1.3 km, which is over 30% of its total length in 32 years. The glacier is separated from the headwall glacier, which can still shed avalanches onto the lower glacier. It is possible that with additional retreat another lake will be revealed in this valley.  The substantial retreat here is comparable with that of nearby Argentina glaciers such as Pico Alto Glacier and Lago Cholila .  The retreat is greater than on Tic Toc Glacier to the southwest in Chile.

Turbio Glacier retreat from 1998 to 2017 in Landsat images.  Red arrow is 1986 terminus location, yellow arrow 2018 terminus location and pink arrow glacier across the border in Chile.

Turbio Glacier in a Digital Globe image from 2013.  Red arrow is 1986 terminus location, yellow arrow 2018 terminus location, blue arrows show glacier flow and pink arrow glacier across the border in Chile.  The border is also indicated.