September 20, 2022
Nizkiy Glacier, Novaya Zemlya Embayment Drains via Terminus Breach
Posted by Mauri Pelto
Nizkiy Glacier in Sentinel images from July 15 and Sept. 17 2022, before and after the breach of the terminus. Point A-D indicate emerging land due to falling water level as the embayment drains. The former outlet (O) is also noted.
Nizkiy Glacier is on the west coast of the island reaching the Barents Sea Coast. 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. Pelto, (2016) noted the contined expansion of an empbayment between the central teminus and a peninsula.
Nizkiy Glacier in Landsat images from 1990, 2015 and 2022 indicating the reduction in width of the terminus ice dam for the embayment. Red arrows=1990 terminus, yellow arrow the 2015 terminus.
In 1990 the Nizkiy Glacier has several termini in lakes and one in the Barents Sea. The main terminus extends north beyond the end of a peninsula in 1990, with an embayment developing from the peninsula across to the northern edge of the terminus. The middle terminus ends in a proglacial lake and in 1990 the terminus largely envelops an island in the lake. The southernmost terminus is in a proglacial lake shown is indicated by a red arrow as well. The 2015 Landsat image indicates the continued reduction in Nizkiy Glacier width reaching the peninsula at the yellow arrow, from 4 km in 1990 to 1.5 km in 2015, having retreated 1200 m from the 1990 position on the northern edge. Hence, it will likely be quite soon when the proglacial lake with the island joins with the Barents Sea. In early July 2022 the terminus tongue width impounding the lake had been reduced to 600 m, the embayment water level was higher than sea level indicating limited drainage under the glacier tongue with the main outlet still being at the southern end of the embayment, Point O. By early September the glacier tongue had been breached and the embayment had drained lowering water level. The drainage channgel is 200 m wide. This has exposed ~2 km2 of new land after embayment drainage. The glacier has lost 15 km2 of area from 1990-2022. The retreat of this glacier has been less than at Vilkitskogo Glacier, will the loss of this pinning point accelerate retreat now?
Closeup view in Sentinel 2 image from 2022. The breach is 200 m wide and has lowered water level in the embayment exposing 2 km2 of new land.
“The retreat of this glacier has been less than at Vilkitskogo Glacier, will the loss of this pinning point accelerate retreat now?”
Clearly this is a rhetorical question, everything is accelerating.
Farewell cryosphere, the truth is we never loved you, enough.