glacier retreat new island – From a Glaciers Perspective

Climate change has been driving the recession of glaciers and ice sheets, which in turn has been changing our maps. One notable category of physical geographic features indicative of the change due to the retreat is the formation of new islands. Below is a list of new islands that this blog has identified and reported. This is not a comprehensive list of all islands that have been formed.

Upernavik Glacier, Greenland in Landsat images from August 2000 and August 2016. Each Point is at the same location in both image, and the changes are noted in the discussion below. The same locations are also identified in the July 2001 and Aug. 2016 image below.

Kong Oscar, Greenland: Island A forms with B and C on the verge.

Steenstrup Glacier, Greenland front in 2015 and 2017 illustrating location with respect to the new islands at: Red Head-red arrow, Tugtuligssup Sarqardlerssuua at yellow arrow , and the 2017 new island at orange arrow. Yellow dots indicate icefront and purple arrow another future island to be released from the glacier.

Coronation Glacier, Canada: A Landsat image from 1989 and a Sentinel 2 image from 2016 illustrate the retreat of Coronation Glacier. Red arrows indicate the 1989 terminus and yellow arrows the 2016 terminus location. Purple numbers 1-5 indicate locations of tributary retreat or thinning. Purple numbers 6-9 are icecaps that did not retain snowcover in 2016.

Chernysheva Glacier and Borozova, Novaya Zemlya comparison in 1990 and 2015 Landsat images. Red arrows indicates 1990 terminus and yellow arrow 2015 terminus position. Island has formed at the 1990 terminus position of Chernysheva.

Tasija and Krayniy Glacier, Novaya Zemlya: Tasija Glacier (T) and Krayniy Glacier (Ky) compared in 1990 and 2015 Landsat images. Red arrows indicate 1990 terminus positions, yellow arrows 2015 terminus positions and purple arrows upglacier thinning. A new island formed upper right red arrow.

Nizkiy Glacier, Novaya Zemlya: Nizky Glacier (N) and Glasnova Glacier (G) compared in 1990 and 2015 Landsat images. Red arrows indicate 1990 terminus positions, yellow arrows 2015 terminus positions and purple arrows upglacier thinning. An island has formed at the second red arrow from the bottom.

Krivosheina Glacier, Novaya Zemlya: Krivosheina Glacier compared in 1990 and 2015 Landsat images. Red arrows indicate 1990 terminus positions, yellow arrows 2015 terminus positions and purple arrows upglacier thinning. Point A indicates a new island that has formed.

Vilkitskogo Glacier, Novaya Zemlya: Vilkitskogo South Glacier (Vs) and Vilkitskogo North Glacier (Vn) compared in 1990 and 2015 Landsat images. Red arrows indicate 1990 terminus positions, yellow arrows 2015 terminus positions and purple arrows upglacier thinning.

Vasilievebreen, Svalbard: retreat from 1990-2017 has led to the creation of one island at the pink arrow, while the island at the orange arrow has eroded and an island at the white arrow is on the verge of being released by the glacier.

Samarinbreen, Svalbard: Landsat imagery from 1990-2014 illustrates that the retreat of the glacier has been 2.1 km including the formation of an island.

Comparison of glaciers terminating in Lednikovoye Lake in central Svalbard in 2000 and 2016. Red arrow is the 2000 terminus location and yellow arrows the 2016 terminus location.

Lednikovoye Lake in central Novaya Zemlya has four glaciers terminating in it. Here we examine the two unnamed glaciers that discharge into the northwest portion of the lake. The glaciers are retreating like all tidewater glaciers in northern Novaya Zemlya, though they are not specifically tidewater (LEGOS, 2006). LEGOS (2006) identified a 2.7 square kilometer reduction in area of the two glaciers from 1990-2000. 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 use Landsat images to examine changes from 1999 to 2016.

In 1999 and 2000 the western Lednikovoye Glacier ended on an island, the eastern Lednikovoye Glacier extended past the exit of a glacier filled valley entering from the east. By 2016 the western terminus had retreated 800 meters from the newly developed island. The eastern terminus had retreated a similar amount now ending near the center of the valley entering on the east. The glacier in that eastern valley has retreated 600 m from 1999 to 2016. The snowline in 2000 and 2016 is at ~500 m, with a significant remaining accumulation zone. There is limited upglacier thinning suggesting that retreat will not become rapid. The reduced rate of retreat of the Lednikovoye Glacier’s versus tidewater glacier of Novaya Zemlya suggests the importance of both sea ice reduction and sea surface temperature increase to the retreat rate of the latter such as Krayniy Glacier, Tasija Glacier and Chernysheva Glacier.