May 28, 2015
Retreat forms Embayment at Kropotkina Glacier in Novaya Zemlya
Posted by Mauri Pelto
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.
1988 Landsat image
1998 Landsat image
2011 Landsat image
2014 Landsat image