Chernysheva Glacier is on the northwest coast of Novaya Zemlya. The glacier terminates in the Barents Sea and has been retreating like all tidewater glaciers in northern Novaya Zemlya (LEGOS, 2006) This glaciers retreat follows the pattern of Krivosheina, Roze and Sredniy and Taisija Glacier. In this post we examine the changes using Landsat imagery from 1988, 2006 and 2011. The flow of the glacier from the main ice cap is indicated by blue arrows. The yellow arrow in each image indicates an island, the red arrow a bedrock ridge that extends under the ice, and the pink arrow the east margin of the terminus in 1988.
Google Earth image
In 1988 the glacier ended on the island which is a pinning point that would limit calving at the time. The 1988 image is very clear and the ridge with the bulge in the ice over it seems to extend 70% of the way across the glacier. In 2006 the glacier has pulled back from the island, there is however sea ice between the glacier front and the island, which has several icebergs embedded in it. By 2011 the glacier retreat from this island is 3100 m. The retreat from the east margin is 2600 m. The bedrock ridge at the red arrow should provide some stability and slow the retreat rate on the west side, it does not appear to extend to the eastern margin and this may continue to retreat apace. Interestingly the embayment here is very similar to that of Nizkiy and Glasova Glacier, which must be due to the similar geology. The reduction in duration of Barents Sea ice cover ice in front of the glacier has certainly helped to increase recent retreat.
1988 Landsat image
2006 Landsat image
2011 Landsat image
Krivosheina Glacier is a tidewater glacier on the northwest coast of Novaya Zemlya ending in the Barents Sea. A recent study by LEGOS (Laboratoire D’Eetudes en Geophysicque et Oceanographie Spatiales) in France highlights the changes of these glaciers from 1990-2000. They note that Krivosheina Glacier lost 3.3 square kilometers of area due to retreat in that decade. Given the recent reduction in Arctic Sea Ice in the region, these glaciers are facing dramatic climate changes. Here we examine satellite imagery from 1988, 2009 and 2011 to identify glacier change. In 1988 the glacier ended on an island, labelled Point A on each image. The north edge of the terminus turned the corner into northwest into a bay just west of Point B. The southern side of the terminus ended at the nose of a ridge just west of Point C. By 2009 a deep water channel was present between the island and the terminus. The north side of the terminus ended just south of Point B and the southern side of the terminus had retreated across the side valley to the east of Point C. By 2011 the terminus had retreated 2 km from its 1988 terminus position on the island and 1400 meters at the south side near Point C. Given that the glacier is 4.6 km wide, this retreat that averaged 1.6 km equals an area loss of 7 square kilometers since 1988. This retreat is similar to that of Nizkiy and Glazova Glacier just to the south and Roze and Sredniy Glacier on the east side of the island.
The glaciers of northern Novaya Zemlya, Russia are truly generally out of sight out of mine. There remoteness and lack of importance as a water resource being the key reasons. A recent study by LEGOS (Laboratoire D’Eetudes en Geophysicque et Oceanographie Spatiales) in France highlights the changes of these glaciers from 1990-2000. It seems particularly important to pay attention to these glaciers due to the recent changes in sea ice cover that have left a much longer duration of open water around the island particularly to the west in the Barents Sea. This has been beautifully illustrated in a post at Arctic Sea Ice Blog this week. . Here we focus on two glaciers, Nitzky and Glasova on the west coast of the island that LEGOS identified as losing 1.2 and 1.4 square kilometers in area from 1990-2000 LEGOS (Alexei Kouarev, Frédérique Rémy and Benoit Legresy) a. Here we compare a Landsat image from 1988 and 2009. The northern glacier of the two is Glazova, the burgundy arrows and dots indicate the terminus in 1988. In the 2009 image the terminus is orange dots. Glazova Glacier has retreated 1500 meters. The Nizkiy Glacier has several termini in lakes and one in the Barents Sea. Along the northern margin inland of the terminus in 1988 the green arrow indicates a proglacial lake, trapped by the glacier. In 2009 the lake has drained, green arrow and the green dots indicate the path by which the lake drained. Marginal retreat of 500 meters opened up a passage for drainage. The main terminus juts north out beyond the end of a peninsula, by 2009 the terminus has retreated 1000-1500 meters enough to leave this terminus exposed, note the burgundy dots on both images. The middle terminus ends in a proglacial lake and in 1988 the terminus largely envelops an island, yellow arrow. By 2009 the glacier has exposed almost all of this island a 1000 meter retreat. The southernmost terminus shown is indicated by a black arrow. In 1988 the piedmont lobe of this glacier almost completely fills the lake basin. In 2009 the lake basin is half exposed by glacier retreat, this is a 1500 meter retreat. The very map of the region is changing. Below is the 1988 and then 2009 image. After we will zoom in and further discuss the changes on Nizkiy Glacier. .
The yellow arrow indicates the new island forming in the proglacial lake, burgundy arrow indicates the peninsula that the main marine terminus extended beyond in 1988 and the green arrow indicates the edge of the valley through which the formerly trapped lake could drain. It will likely be quite soon when the proglacial lake with the island joins with the Barents Sea. This region has quite limited Landsat imagery making it hard to determine how much retreat occurred in 2011. The last image is a MODIS image from 8/31/2011, where the burgundy arrow indicates the peninsula at the end of Nizkiy Glacier. This retreat fits the pattern of retreat and changes in geography from retreat further NE in Novaya Zemlya at Roze and Sredniy Glacier and elsewhere on the northwest coast, Krivosheina Glacier.