February 15, 2018
Comparison of glaciers around Gora Gvandra, Caucasus Mountians in 1985 and 2017 Landsat images. G=Gvandra Glacier, D=Dalar galcier, DN =North Dalari Glacier, S=Sakeni Glacier and M=Morde Glacier.
Gora Gvandra Mountain is southwest of Mount Elbrus of the Caucasus Mountains of Georgia and is surrounded by a group of glaciers that in recent years have not exhibited an accumulation zone. Stokes et al (2006) note that 94% of Caucasus Mountain glaciers retreated from 1985 to 2000. Tielidze and Wheate (2018) updated these observations to 2014 documenting the 1986 glacier surface area at 1482 square kilometers decreasing to 1193 square kilometers by 2014, a 29% decline. Here we examine Landsat images from 1985 to 2017 to illustrate the profound changes. In 2017 five of the six glaciers in the area had no retained snowpack, like the Alps this was a summer of high melt.
A comparison from 1985 to 2017 of Dalari North Glacier (DN), pink arrow indicates the glacier ending in a lake in 1985 and 1998, and terminates short of the lake in 2013. In 2013 the accumulation zone is small and in 2017 the accumulation zone does not exist. Note the contraction of the unnamed glacier from 1985-2017 at the green arrow, with an expanding bedrock area in the midst of what was the glacier and no retained snow in 2017. The Morde Glacier (M) terminus separated around a bedrock knob at the orange arrow in 1985 and the western arm terminates beyond the knob. The glacier has retreated 400 m by 2017, driven by a the lack of an accumulation zone with no retained snowpack in 2013 or 2017. The terminus of Dalar Galcier (D), yellow arrow, is below a steep slope in 1985 and 1998. By 2013 the steep slope is bare rock separating the former terminus from the rest of the glacier. In 2017 there is no retained snowpack on the glacier. Gvandra Glacier has lost all of its snowpack in 2017. The Sakeni Glacier has a 500 m wide terminus tongue in 1985 and 1998, white arrow. By 2013 and in 2017 the tongue has narrowed to 150 m and is going to either separate from the upper glacier or melt away soon. There is retained snowpack on the upper part of Sakeni Glacier in each year.
Of the six glaciers examined only one glacier had an accumulation zone in 2017 and in 2013 the accumulation zone was only significant on one glacier. Pelto (2010) noted that a glacier cannot survive without a persistent and consistent accumulation zone. This has been noted to be case even on some larger glacier of Mount Elbrus. Psysh Glacier in the western Caucasus is also disappearing.
Comparison of glaciers around Gora Gvandra, Caucasus Mountians in 1985 and 2017 Landsat images. yellow arrow=Dalar glacier, pink arrow=North Dalari Glacier, whtie arrow=Sakeni Glacier and orange arrow=Morde Glacier.