Qorqup Glacier (Qooqqup) is in southern Greenland near Narsarsuaq. The glacier divides shortly above the terminus into an eastern and western glacier branch. Kuussuup Sermia is a distributary glacier of the Qorqup. Here we examine Landsat imagery from 1993 to 2014 and Google Earth imagery from 2005 and 2013. The eastern branch terminus is indicated by the red arrow.
A series of images from 1993 to 2008 indicate limited terminus change, the red arrow indicates the 1993 terminus position on each image. The main change was the minor retreat on the western side of the terminus between 1993 and 1997, where a 600 m wide and 600 m long area was lost. After 2010 the glacier retreated 750 m by 2014. However, in 2014 it is clear that the lower 3 km of the terminus is disintegrating. The disintegration is evident at the pink arrows, with both rifts and iceberg melange sections evident. The Google Earth imagery from 2005 and 2013 indicate a vast change in the character of this terminus reach. In 2005 the terminus is still at the same location, red arrow. The pink arrows indicate crevassing that indicates rapid glacier flow, there is no significant rifting or melange at that time. By 2013 the glacier has retreated from the red arrow at the 1993-2010 terminus position. More importantly each pink arrow indicates an substantial rift or ice melange. The glacier tongue is no longer in contact with the valley walls in its last two kilometers, three kilometers on the east side. There is also a large rift two kilometers from the ice front, indicating a location where the glacier will separate. This rift does penetrate to the water level. The retreat of this glacier is similar to that of Narssap Sermia and Qaleriq Glacier. The rifting leading to calving is what was observed on Petermann Glacier.
1993 Landsat image
1997 Landsat image
2004 Landsat image
2010 Landsat image
2014 Landsat image
2005 Google Earth image
2013 Google Earth image
Koge Bugt Glacier is an outlet of the Greenland Ice Sheet on the southeast Coast. The glacier empties into the bay of the same name, and has three main calving fronts. This glacier is the the sweet spot for high snowfall and hence, despite its smaller size is one of the larger outlet glaciers in terms of volume. Koge Bugt Glacier is not an oft mentioned glacier it is not as fast as Helheim or Jakobshavn, does not have as long a calving front as Humboldt Glacier. Does not calve icebergs nearly as large as Petermann Glacier. Does not penetrate into the midst of the ice sheet as far as Zachariae Ice Stream or 79 Glacier. However, according to observations of Enderlin et al (2014), Koge Bugt has the second largest volume flow for the entire ice sheet. They further note that the glacier has had the third greatest volume anomaly since 2000, that is increase in discharge. Murray et al (2010) indicate Koge Bugt had accelerated and thinned in concert with other glaciers in the region. The second image below is Figure 1 from their paper indicating the 27,000 square kilometer drainage area of Koge Bugt.
Howat and Eddy (2011) examing 210 outlet glacier in Greenland noted that 191 retreated from 2000-2010 including 89% in SE Greenland. Howat and Eddy (2011) data indicated limited retreat of Koge Bugt Glacier before 2000. From 2000 to 2010 they noted a retreat of 2300 m of outlet C, 1650 m for outlet B and 300 m for outlet A. Each of these outlets has a heavily crevassed active calving front having widths of 5000 m for A, 3500 m for B and 3500 m for C. Outlet B has calved a large iceberg, and there is a substantial rift near the calving front.
Greenland Velocity map with Koge Bugt indicated by red arrow.
Koge Bugt Drainage area from Murray et al (2010)
Danish Geologic Survey map of Koge Bugt area, outlets labelled A-C.
Google Earth image outlet A
Google Earth image outlet B
Google Earth image outlet C
Below is a sequence of Landsat images from 2001-2013 of the Koge Bugt Glacier three main termini. In each case the red dots indicate the calving front, the purple arrow is at the same spot on the north side of terminus A, the yellow arrow at the same spot on the west side of terminus B and the red arrow at the same spot on the west side of terminus C. From 2001 to 2011 terminus A has retreated little on the south side, but has retreated 1.5 km on the north side. Terminus B has retreated from halfway along the island on the southwest side of the terminus to the north of this island by 2011, a retreat of 2.2 km. Terminus C has retreated beyond the north end of the Peninsula noted by the red arrow, a distance of 600 m. Given the size and velocity of Koge Bugt this is a minor retreat, that can be erased by a year with more limited calving. The melt zone in these July and August images indicates how limited the ablation zone is compared to the west side of the ice sheet, this also limits the occurrence of supraglacial lakes.
Landsat Image 2001
landsat Image 2002
Landsat Image 2005
Landsat image 2010
Landsat image 2011
Epiq Sermia is an outlet glacier of northwest Greenland, 70 km north of Jakobshavn Glacier. Epiq Sermia discharges 2-3% of the ice volume that Jakobshavn discharges. The glacier was observed to have had a small retreat in the first half of the 20th century and a minor advance in the 1960’s. Currently it is undergoing a more rapid retreat. This outlet glacier behaves as other Greenland marine terminating outlet glaciers, thinning at the terminus induced by greater basal and surface melting, triggers thinning which reduces basal friction and allows for acceleration and retreat. The glacier and its neighbor Kangilergnata Sermia have attracted recent research Rignot et al (2010) examined melting beneath the terminus tongue of both glaciers. They found rates of submarine melting 100 times larger than surface melt rates, but comparable to rates of iceberg discharge. Rignot et al (2010-PR) identified melt along the submerged bottom of Kangilergnata and Epiq Sermia where it comes into contact with warm ocean waters, which melts the glacier bottom, thinning the ice, shifting its grounding line, increasing its flotation, which leads to retreat. Figure 1 from Rignot et al (2010) indicates that water depths at the calving front are between 200-300 m deep, not that deep for the ice thickness observed..
A comparison of a 2001 and 2011 Landsat image overlain on Google Earth imagery identifies recent changes. The image comparison indicate average retreat of 1.1 kilometers over the 10 years for Epiq Sermia and 2.5 km for Kangilergnata Sermia, the yellow line is the 2001 margin and red line the 2011 margin. Thinning of Epiq Sermia is also apparent in the retreat upglacier from the terminus with the trimline being exposed and retreat at the secondary terminus into the lake. Retreat of the Epiq Sermia and Kangilergnata Sermia mirror that of other outlet glaciers, Howat and Eddy (2011) found that from 1964-2010 64% were retreating and from 2000-2010 98% of the outlet glaciers in NW Greenland were retreating. The also noted the average retreat rate rose from 20 m/year to 125 m/year, Howat and Eddy (2011). Specific examples of Umiamako Glacier, Upernavik Glacier and Kong Oscar Glacier.
A paper by Mernild and others (2011) focusses on the Mittivakkat Glacier on the east coast of Greenland. The glacier is separate from the Greenland Ice Sheet and its climate response as a result more rapid and more similar to other alpine glaciers. Mernild and others (2011) observe that the glacier has retreated 1300 meters since 1931 and that it has had a considerable negative mass balance since 1995. Sebastian Mernild at the Climate, Ocean, and Sea Ice Modeling Group, Computational Physics and Methods, Los Alamos National Laboratory, Los Alamos, New Mexico has provided the pictures that document the terminus change. The field observations is completed in conjunction with Aarhus University and University of Copenhagen, both in Denmark. Notice the glacier ends just short of the coastline in 1931, but in 2006 is 1500 meters from the coastline. Mittivakkat Glacier has a mass balance record since 1995, that is reported to the World Glacier Monitoring Service. During the 1995-2010 period the glacier’s average balance has been -0.87 meters/year. The cumulative loss is -13 m, with the highest loss being in 2010 at -2.16 m. The 13 m loss in water equivalent snow-ice is equivalent to more than 14 m of ice thickness and 15% of the glaciers entire volume. The problem for the glacier is the loss of essentially all of its snow cover in four of the last ten years, this is not a recipe for long term glacier survival (Pelto, 2010). The image immediately below is a Digital Globe image from July 2005 indicating the snow covered area with six weeks left in the melt season is already limited, the glacier is in the center of the image and is the largest ice mass by far. The middle image from 2006 has areas of firn exposed indicated with blue arrows, this is not the end of the melt season yet. The lower image is from August 26 2010 and is a MODIS image catalogued by the Danish Meteorological Institute.The arrow indicates the glacier which has only 10% snow covered area, with a couple of weeks of melting left in the season. In 2010 air temperatures at Tasiilaq a few kilometers from the glacier were in the range of 1.5 C above average leading to twice the normal melt rate at the terminus, which will generate an even more rapid retreat for 2010 and 2011. The high temperatures in 2010 were not limited to this location as noted by Jason Box of Ohio State. The high melt rates were as a result not limited to the Mittivakkat Glacier as observed by the record melting reported in the Arctic Report Card. The recent large negative balances will generate ongoing retreat. Mernild observes that in 2011 the mass balance was even larger than -2.45 m An image provided by Sebastian Mernild indicates a whole in the glacier near the terminus, indicating rapid retreat in the near future.