Kropotkina Glacier retreat – From a Glaciers Perspective

Kropotkina Glacier, Novaya Zemlya in 1988 and 2019 Landsat images. Red arrow marks the 1988 terminus location and yellow arrow the 2019 terminus location. Point A and B mark nunataks in 1988.

Kropotkina Glacier is a tidewater glacier on the southeast coast of Novaya Zemlya that drain into Vlaseva Bay. The glaciers terminate in the Kara Sea and has been retreating like all tidewater glaciers in Novaya Zemlya LEGOS, 2006 . The map shown below from this project indicates the lack of an embayment in 1952, red dashed line and limited retreat from 1952-1988. Carr et al (2014) identified an average retreat rate of 52 meters/year for tidewater glaciers on Novaya Zemlya from 1992 to 2010 and 5 meters/year for land terminating glaciers. Carr et al (2017) found that between 2000 and 2013, retreat rates were significantly higher on marine-terminating outlet glaciers than during the previous 27 years. Here we examine Landsat imagery from 1988 to 2019 to identify changes in Kropotkina Glacier.

In 1988 the southern terminus is at the red arrow indicating a peninsula on the east side of the terminus, while the northern terminus is at the margin of a proglacial lake. Point A and B are nunataks. In 1998 the southern terminus has not changed significantly. The northern terminus has not retreated significantly, but the proglacial lake has drained. By 2015 the terminus tongue in the embayment has largely collapsed, though a tongue of ice reaches across this embayment. An area of more 7 km² has gone from glacier ice to embayment since 1998. Point A is no longer a nunatak as marginal retreat has reached this point. The snowline in 2015 is also higher than is typically observed extending beyond the image area and is above 800 m.

By 2019 the main embayment is free of ice, having expanded by 12 km², as the result of terminus retreat. The terminus is now oriented north-south with a 6 km long calving front. The 2019 snowline is at 750 m.Point B remains a nunatak, but not for long with the continued high snowlines seen in 2015, 2018 and 2019. The retreat has mainly been via calving, and with an expanding calving front and reduced pinning points along the margin, the rapid retreat and area loss is not over. How deep the water is at the calving front will determine how limited calving will be going forward. The retreat of this glacier is substantial as has been the norm for tidewater glaciers such as Inostrantseva Glacier, Vera Glacier, Mack and Velkena Glacier or Chernysheva Glacier, with the formation of new islands and glacier separation common place Pelto (2017) and GlacierHub.

Kropotkina Glacier, Novaya Zemlya in 1998 and 2015 Landsat images. Red arrow marks the 1988 terminus location and yellow arrow the 2019 terminus location. Point A and B mark nunataks in 1988.

Map of the region from LEGOS, 2006 with elevations indicated.

Kropotkina Glacier is a tidewater glacier on the southeast coast of Novaya Zemlya that drain into Vlaseva Bay. The glaciers terminate in the Kara Sea and has been retreating like all tidewater glaciers in Novaya Zemlya LEGOS, 2006 . The map shown below from this project indicate the lack of an embayment in 1952, red dashed line and limited retreat from 1952-1988, with 1988 being the yellow line. Carr et al (2014) identified an average retreat rate of 52 meters/year for tidewater glaciers on Novaya Zemlya from 1992 to 2010 and 5 meters/year for land terminating glaciers. Here we examine Landsat imagery from 1988 to 2013 to identify changes in Kropotkina Glacier.

In each image the colored arrows are in the same location. In 1988 the terminus is just beyond the red arrow indicating a peninsula on the east side of the terminus. The yellow arrow indicates a lake beyond an eastern terminus lobe with limited drainage down a river adjacent to the glacier, purple arrow. Two smaller glacier termini are joined at the green arrow. By 1998 there is a minor retreat of the main terminus on both the east and west side. Little change is seen elsewhere. By 2011 a substantial embayment has developed above the red arrow. Retreat is limited on the western side of the terminus. The eastern terminus lobe has retreated as well and the drainage channel adjacent to the glacier is less restricted leading to a less extensive lake. The lake is mostly filling the region occupied by ice 13 years before.

In 2014 there is cloud cover over much of the glacier but the terminus is clear. The easternmost terminus lobe is collapsing, and is not surrounded by a lake, yellow arrow. The purple arrow drainage river is no longer necessary as there is lake connectivity. The main terminus to the east has retreated to the entrance to the lake for the eastern terminus lobe, this a 2.8 km retreat. The western side of the glacier remains aground on a peninsula, but has receded 500 m. How long before this part of the terminus to retreats into the expanding embayment. An are of more 7 square kilometers has gone from glacier ice to embayment in the last 25 years, almost all within the last 13 years. The retreat has mainly been via calving, and with an expanding calving front and reduced pinning points along the margin, the rapid retreat and area loss is not over. The beginning of rapid retreat coincides with the onset of rapid decline in sea ice extent in the Kara Sea (Perovich et al., 2014).

This ongoing retreat is illustrated by Krivosheina, Chernysheva, Roze and Sredniy and Taisija Glacier also in northern Novaya Zemlya.