December 20, 2022
Lekhziri Glacier, Georgia Retreat Leads to Separation 1996-2022
Posted by Mauri Pelto
Lekhrziri Glacier in 1996 and 2022 Landsat images illustrating the retreat and separation of the three tributaries central (Lc), eastern (Le) and western (Lw). Red arrow indicates 1996 terminus and yellow arrows the 2022 terminus locations
Lekhrziri Glacier has been the largest glacier in Georgia, and was until 2011 a compound glacier comprised of three tributaries joining a short distance from the terminus (Tielidze et al 2016). Tielidze et al (2015) observed in 2011 that the central tributary separated from the east and west tributary that year at the headwaters of the Mestiachala River Basin. From 2000-2020 Lekhziri Glacier experienced the largest retreat, of 1395 m, of 16 large Caucasus glaciers examined by (Tielidze et al 2022). Here we examine Landsat and Sentinel imagery from 1996-2022 to illustrate the changing nature of this glacier.
In 1996 the three tributaries joined at 2300 m and then flowed jointly south for 1 km to the terminus, red arrow on Landsat image. The August snowline is at 3300 m. By 2013 the central glacier has visibly separated by 500 m from the other tributaries. The primary terminus has had a retreat of ~500 m since 1996. The August snowline is at 3400 m in 2013. In 2022 additional retreat as separated the east and west tributaries, with an evident river emanating from each tributary, yellow arrows, feeding into the Mestiachala River. The central tributary terminates 800 m from the former junction. The retreat of the east tributary has been 1.3 km since 1996 and the west tributary 1.25 km since 1996. There is also a small lake that is evident, green arrow, in 2022 that will fill in with sediment. The snowline at the end of August 2022 is at 3450 m. The persistent high snowlines due to warm melt season conditions has led to ongoing mass loss that will lead to continued declines in the Lekhziri Glacier system. This is one example of the widespread retreat of glaciers in the region chronicled by Levan Tielidze. The high snowlines of 2017 and 2022 have been noted for Gora Gvandra glaciers and Zeno Svaneti glaciers.
Lekhrziri Glacier in 2013 Landsat image illustrating the retreat and separation of the three tributaries central (Lc), eastern (Le) and western (Lw). Red arrow indicates 2013 terminus and purple dots the snowline.
Lekhrziri Glacier in 2022 Sentinel image illustrating the retreat and separation of the three tributaries central (Lc), eastern (Le) and western (Lw). Yellow arrows the 2022 terminus locations aand green arrows the small lake at headwaters of Mestiachala River Basin.
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