Posts Tagged svalbard glacier retreat

Svitjodbreen Retreat, Northwest Svalbard

Svitjodbreen is a 10 km long tidewater outlet glacier in northwest Svalbard, Albert Land. The glacier drains north into Fugelfjorden, the highest elevation of the main glacier is 600 meters with a few neighboring peaks reaching 800 m, not very high. NW Svalbard is a region that has experienced extensive long term thinning from 1965 to 2007 (Nuth et al, 2010), with an average glacier wide thinning of 0.5 m/year and frontal thinning of over 1 m/year. nw svalbardjarlbreen overview copyThe retreat is similar to that of Southern Svalbard at Hornbreen and Hambergbreen and much faster than in Eastern Svalbard at Edgoya. Here we examine Landsat images from 1987, 2000 and 2011 and a Google Earth image from 2009. In each image there are four fixed points: Point A is on the south side of the ridge just south of Rissabreen. Point B is at a small peak, Hirdfjellet. Point C is at the beginning of the Skutelen Peninsula just south of Hirdfjellet and Point D is a small bedrock ridge. In 1987 the terminus extends across the 2 km wide fjord one kilometer north of the ridge on the west side of the glacier labelled A and extends directly across the fjord to Point B. Point D is 3 km behind the glacier front and Point C is 1.5 km from the ice front. By 2000 the western side of the terminus has retreated nearly 500 meters and the east side by Point B very little. In 2011 the terminus has retreated beyond the bedrock ridge at Point A and extends across the fjord to Point C. The bedrock Point D is now just 1.6 km from the glacier front. Jarlbreen has retreated 1200 to 1500 meters from 1987 to 2011, with most of the retreat occurring after 2000.

jarlbreen 1987

jarlbreen 2000
jarlbreen 2012
The front of the glacier is heavily crevassed indicating considerable calving activity. Google Earth refers to this glacier as Jarlbreen, but Jarlbreen is east of the Skutulen Peninsula. The ridge at Point D has expanded as the glacier has thinned. Oerlemans et al (2011) noted a similar retreat rate for Hansbreen. They further determined that calving losses were of the same magnitude as melting losses. jarlbreen ge

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Albrectbreen, Svalbard retreat and thinning

Albrechtbreen is a glacier draining the northeast side of the Edgoya Ice Cap. James et al (2012) report that the glacier retreated at a rate of 33 m/year from 1971-2000 and 64 m/year after 2000. The glacier terminates on an outwash plain at 50 meters, and begins from the ice cap at 300 meters. From 1971-2005 the ice cap has had a mass balance loss of -0.6 m/year (Nuth et al, 2010). The Albrechtbreen has had a more negative mass balance losing 34 m in thickness, essentially 1 m/year (James et al, 2012). The thinning has not been isolated to the margin of the glacier, with the greatest thinning occurring at 150 meters. The retreat and thinning is identified in the Figure from James et al (2012). In this post Landsat imgery from 2002, 2005 and 2010 is utilized to identify marginal changes and upglacier thinning. The blue dots in each image indicate the snowline, the yellow arrow a distinctive lake beyond the terminus that can be used to gage the retreat from 2002 to 2010, and the blue and violet arrows indicate locations where bedrock exposure has expanded as the glacier has thinned. The terminus in the vicinity of the lake has retreated 450 meters in eight years, 55 meters/year. . That the thinning extends to the highest areas of the Albrectbreen is not a good sign for its long term survival. The lack of snowcover can be a bit deceiving since much of the accumulation on this glacier is superimposed ice. That is meltwater that is refrozen before escaping the glacier.

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Hornbreen-Hambergbreen Retreat Svalbard

Hornsund is a fjord that in 2010 almost cuts through the southern Island of Svalbard. The Institute of Geophysics Polish Academy have 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. At that time the eastern end of Hornsund was fronted by a single glacier terminus comprised of the Sotrbreen (ST), Hornsbreen (HO), Svalisbreen (SV) and Mendelejevbreen (ME). By 2010 retreat has led to the separation of these four glaciers. The top image is the map superimposed on the Landsat image both below, from commenter Andylee. Pälli et al (2003)in a joint University of Oulu, Finland and University of Silesia noted that Hornbreen has retreated by 13.5 km from the central part of the front, and Hambergbreen (HA) by 16km from 1901-2000. As part of this project surveys of the basal topography beneath the glaciers was examined.
Moore et al, 2003) found that there is not a below sea level connection underneath the Hornbreen-Hamberbreen divide that would separate Sorkappland from Torrelland. The ice divide of Hornbreen-Hambergbreen is below the local snowline at 300 m and Pälli et al (2003) indicate that this connection cannot survive current climate. Kvamstø et al (2011) in a Bergen University led study noted the melt season had increased by more than two weeks in Svalbard from 192-2010. In 1983 the distance from the terminus of the Hornbreen to the terminus of Hambergbreen was 17 km. In 2010 the distance is 9 km, as seen below. . A comparison of locations in the 1983 map and the 2010 Landsat image indicate the retreat from 1983 to 2010 has been approximately 5.5 km for Storbreen, 6 km for Hornbreen, 3 km for Svalisbreen and 1.5 km for Mendelejevbreen. . The retreat of the glaciers at the head of Hornsund follow the pattern of other glacier in the region Nannbreen and Hansbreen.

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Retreat of Hansbreen, Svalbard

Hansbreen is tidewater glacier flowing into Hornsund in sw Svalbard. The glacier has been examined in detail over the last twenty years from the Polish Research Station. The glacier has retreated 2.7 kilometers from 1900 to 2008. The chart below from Oerlemans, Jania and Kolandara (2011) illustrates this retreat as does the comparative images from the Polish Research Station. The glacier mass balance has been measured since 1989 and is submitted to the World Glacier Monitoring Service. In a detailed review of this calving glacier Oerlemans, Jania and Kolandra (2011) report that The average surface mass balance has been -0.36 meters per year, but this is equaled by the calving loss, leading to a loss of 0.8 meters per year. The low slope of this glacier 1.6 degrees makes it difficult to reestablish equilibrium as it retreats. The bed of the glacier remains below sea level for at least 70% of its length, note Figure 3 in Oerlemans et al (2011). The glacier retreated 400 meters from 2000-2005, and has continued this rate of recession. In the two side by side Landsat images below from 2001 (right) and 2010 (left) changes are evident at the front of the neighboring Paierbreen-circle, Hansbreen (H) and Nannbreen (A) Focusing just on the Hansbreen a red line from the summit of two adjacent mountains is added to the 2001 and 2010 image to illustrate the terminus change. The 2001 images is on top, 2010 image below.

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Retreat of Nannbreen, Svalbard

Nannbreen is a 5 km long land terminating glacier in southwest Svalbard. The glacier is just north of Hornsund. During the course of the 20th century Nannbreen retreated from its Little Ice Age moraine complex forming a new proglacial lake. The glacier ends at an elevation of 150 meters descending from 600 meters, the snowline in several Landsat images from the last decade has been 400-450 meters. By 2000 (first image below)the glacier had retreated 750 meters from the moraine complex and the glacier ended in a lake, that was over 500 meters long. In 2010 (second image below) the glacier had retreated out of the lake, 250 meters of retreat in 10 years, 1000 meters of retreat in the last century. Certainly the 21st century retreat rate is far above the average 20th century retreat rate. Most of the large glaciers in Svalbard are tidewater calving glaciers, such as the nearby Hansbreen, which retreated 400 meters from 2000-2005. Svalbard glaciers have been losing considerable volume, indicative of negative mass balance and glacier retreat. Nuth et al (2010) concluded that over the past 40 years for Svalbard ice loss is 9.71 ± 0.55 cubic kilometers/year. This is an average thinning of 0.36 meters/year for an annual contribution to global sea level rise of 0.026 mm yr.

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