November 9, 2017

Storbreen, Svalbard Major Retreat Opens New Fjord

Posted by Mauri Pelto

Storbreen, Svalbard in 1990 and 2017 Landsat images.  The red arrows indicate 1990 terminus , yellow arrow the 2017 terminus and purple dots the snowline in 1990.  A recent snow storm has obscured the actual snowline in Aug 2017. 

Storbreen Glacier (ST) terminates on the north side of Hornsund in southern Svalbard.  From 1990 to 2017 Storbreen has experienced a substantial retreat opening a new fjord and separating from Hornbreen (H).  Svalbard is host to 163 tidewater glaciers with a collective calving front of 860 km Błaszczyk et al, 2009). Nuth et al (2013) determined that the glacier area over the entire archipelago has decreased by an average of 80 kmper year over the past 30 years, a 7% reduction. In the most recent period 1990-2007, terminus retreat was larger than in an earlier period from 1930-1990, while area shrinkage was smaller. Hornsund is a fjord that in 2014 almost cuts through the southern Island of Svalbard, and eventually will. The Institute of Geophysics Polish Academy has maintained a Polish Research Station in Hornsund since 1957.  The 1984 map, from the University of Silesia, of the glaciers and geomorphology document the extent of the glaciers in 1983. A more detailed examination by the same researchers, Blaszczyk et al. (2013) reported the total area of the glacier cover lost in Hornsund Fjord area from 1899–2010 was approximately 172 square kilometers. Pelto (2017) reported significant retreat of all 10 major tidewater glaciers of Hornsund Fjord.

In 1990 the terminus of Storbreen on the east side is shared with Hornbreen Glacier (H), joining near the tip of a peninsula that will emerge between the glaciers with retreat.  On the west side the glacier terminates at the southern end of a peninsula.  The snowline is at 400 m in 1990.  In 2002 the glacier has separated from Hornbreen and terminates in a newly opening fjord, with the snowline at 350 m.  In 2013 and 2015 the glacier has retreated substantially up the new fjord with the snowline at 450 m in 2013 and 500 m in 2015.  By 2017 the glacier has retreated 8.7 km in the glacier center from the west margin in 1990, 6.0 km on the centerline and 4.8 km from the east margin of 1990.  The glacier terminus is still tidewater and is 4.7 km wide.  The extensive crevassing at the glacier front in Google Earth imagery, below, indicates continued rapid flow at the terminus.  The retreat continues with significant cahnge after 2013.  The crevassing may indicate a steeper surface slope too.  The topography at TopoSvalbard suggests limited change in surface slope based on older mapping.  The head of the fjord is not likely to occur until at least the junction point of several tributaries. The retreat here is similar to that of adjacent Hornbreen and Paierbreen. 

Storbreen, Svalbard in 2013 and 2015 Landsat images.  The red arrows indicate 1990 terminus , yellow arrow the 2017 terminus and purple dots the snowline.   

The crevassed front of Storbreen in 2014 on left.  Indicating active calving but also suggestive of a steeper slope than before.  The Fjord head does not appear to be near though. 

 

Storbreen, Svalbard in 2002 Landsat image.  The red arrows indicate 1990 terminus , yellow arrow the 2017 terminus and purple dots the snowline.