November 7, 2013

Gora Bashkara Region Glacier Retreat, Western Caucasus, Russia and Georgia

Posted by Mauri Pelto

In the vicinity of Bashkara Glacier in the Western Caucasus we examine using Landsat imagery the response of several glacier over the 1998 to 2013 period. This region has been experiencing widespread significant retreat (Shahgedanova et al 2009), with average retreat of 8 m per year due in large part to increased summer temperatures. This region has been an area of increased proglacial lake formation as well Stokes et al (2007). Petrakov et al (2011) examined changes in the lakes at the margin of Bashkara Glacier. They examined three lakes near the margin of the glacier and identified large expansion of two of them due to glacier retreat. They found the terminus reach to be stagnant and thinned 13 meters from 1999 to 2007. Lake Lapa has expanded eastward 250 m since 1999 due to terminus retreat Petrakov et al (2011). bashkara lakes
Image from Petrakov et al (2011). Lake Lapo=1 and Lake Bashkara=2.

In 1998 only Bashkara Lake is substantial in sie, yellow arrow. Two valleys to the west an unnamed glacier ends at the red arrow after taking a sharp right turn. At the pink arrow an unnamed mountain glacier descends from the upper basin at m to the lower valley where it terminates. In 2001 little has changed at the three locations. By 2013 Lake Lapo the western most lake at the yellow arrow has expanded as the glacier has retreated that Petrakov et al (2011) noted. The unnamed glacier at the red arrow has retreated 500 m and now barely rounds the turn to the west. At the pink arrow the glacier now no longer descends from the upper basin to the lower valley. The terminus region in the valley bottom has melted away, a retreat of 400-500 m. The retreat of these glacier follows that of other glacier in the region Great Azau Glacier, Kirtisho Glacier and Lednik Karaugom Glacier. baykara 1998
1998 Landsat image

baykara 2001
2001 Landsat image

baykara 2013
2013 Landsat image