December 11, 2019

Austre Torellbreen, Svalbard Retreat and Nunatak Expansion

Posted by Mauri Pelto

Austre Torellbreen in 2000 and 2019 Landsat images.  Red arrow is the 2000 terminus location, yellow arrow the 2019 terminus location. Point 1,2 and 3 are nunatak areas that are expanding.

Austre Torellbreen is an outlet glacier on the southwest coast of Svalbard.  It is just west of calving glacier that are retreating such as Paierbreen and Samarinbreen and adjacent to the land terminating Nannbreen. Blaszczyk et al (2008) report the velocity of Austre Torellbreen near the calving front of 220-265 m/year. Nuth et al (2013) determined that the glacier area over the entire archipelago has decreased by an average of 80 km per year over the past 30 years, a 7% reduction.

In 2000 the calving front is 4.7 km wide and has a low slope at the terminus with the surface reaching 150 m 2.5 km from the calving front.  The calving front is at a point where the embayment widens upglacier and has outwash plains on either side of the margin. The snowline is at 300 m in 2000.  At Point 1 is an isolated nunatak and at Point 2 and 3 are limited ridges extending from nunataks. By 2014 the glaciers western margin has retreated into the widening embayment, with more limited retreat in the center and eastern margin of the glacier.  By 2019 the Austre Torellbreen western margin has retreated 2400 m, while the eastern margin has retreated 800 m. The terminus has narrowed to 4.2 km and is retreated from an area of low slope margins to a location between two peak Brattho and Raudfjellet. There is an area of extensive crevassing at the current calving front, suggesting that further calving retreat will occur. At Point 1 the nunatak has expanded in area and vertical relief. At Point 2 the ridge that was separated in two segments has joined into a single ridge.  At Point 3 the ridge has extended by 500 m and has a greater relief in 2019.  The nunataks and mountain ridges that are amidst and adjacent to Austre Torellbreen can be seen to emerge and expand from 2000 to 2019 as the glacier thins.  This thinning leads to the retreat that is enhanced by calving.


Austre Torellbreen in TopoSvalbard map from circa 2000 and in a visual image from 2014.

Austre Torllbreen in 2014 Landsat image. Red dots indicate the snowline at 350 m.