Steenstrup Glacier Retreat, New Island Generation NW Greenland

Steenstrup Glacier is located at 75.2 N in Northwest Greeland. The glacier terminates on a series of headlands and islands, the glacier immediatley to the south is Kjer Glacier. The boundary between Steenstrup Gletscher and Kjer Glacier is Red Head, Steenstrup Glacier’s northern margin is at Cape Seddon. Here we examine changes in the terminus position of Steenstrup and Kjer Glacier from 1999 to 2013. The retreat of the glacier during this interval has led to generation of new islands. Steenstrup Glacier has retreated 10 km over the past 60 years (Van As, 2010). Kjer Glacier was noted as relatively stable until loss of connection with Red Head Peninsula in 2005 (Van As, 2010).
steenstrup map
Image from Van As (2010).

McFadden et al (2011) noted several glaciers in Northwest Greenland Sverdrups, Steenstrup (75°16’15.37”N), Upernavik, and Umiamako that had similar thinning patterns. Each experienced rapid thinning of up to ~100 m a-1 since 2000. They further noted that thinning was not synchronous with Steenstrup and Sverdrups thinning fast from 2002 to 2005, Upernavik from 2005 to 2006, and Umiamako from 2007 to 2008. This is not exactly synchronous, but occurring within a few years is essentially synchronous in terms of glacier dynamics. Each glacier also had a coincident speed-up with a 20% acceleration for Steenstrup Glacier (McFadden et al, 2011). This is a familiar pattern with thinning there is less friction at the calving front from the fjord walls and the fjord base, leading to greater flow. The enhanced flow leads to retreat and further thinning, resulting in the thinning and the acceleration spreading inland. The initial thinning comes from a combination of basal and surface melt.

Here we examine Landsat images from 1999, 2001 and 2013 to identify changes. The red arrow indicates Red Head, which the glacier still reaches in 1999, though the connection is less than 2 km wide. The purple arrow indicates a small nunatak where the Automatic Weather Station utilized by Van As (2010) is located. The nunatak is 1.5 km from the ice edge in 1999. The orange arrow is an island at the ice front, South of the island the ice front is even with the island in 1999. The yellow arrow notes the connection of Steenstrup Glacier to Cape Seddon that is about 4 km wide. In 2001 there is little change in the ice front except at the purple arrow, where retreat has almost brought the nunatak to the terminus. By 2013 the connection to Red Head has been lost, it is now an island, this occurred as noted by Van As (2010) in 2005. Retreat from Red Head is 6 km. There is a substantial embayment south of the island at the orange arrow, indicating 4 km of retreat. North of this island that will soon lose it connection to the ice sheet, the embayment has expanded as well. At the purple arrow the ice front has reached the former nunatak now becoming an island. At the yellow arrow the loss in ice area at Cape Sneddon is greater than at Red head, though a connection may still exist, it is too narrow to measure. The last image below is a 2012 Google Earth image indicating the narrow connection to Cape Sneddon at that time and the strange relict crevasse pattern. It is clear that the end of Cape Sneddon will be in island next summer if not already, the MODIS imagery is not clear enough to distinguish this. The connection to the island at the south end of Kjer Glacier, last yellow dot near bottom has become much narrower since 1999 and will follow the route of Red Head and Cape Sneddon. The retreat here is coincident with the thinning and acceleration and follows the pattern of retreat and new island generation seen at Kong Oscar Glacier, Alison Glacier and Upernavik Glacier.

steenstrup 1999
1999 Landsat Image

steenstrup 2001
2001 Landsat image

Steenstrup 2013
2013 Landsat image
cape sneddon crevasses
Google Earth 2012 image Cape Sneddon.

New Islands Forming Kong Oscar Glacier, NW Greenland

Ongoing glacier retreat changes local maps. For alpine tt can be the formation of new lakes due to glacier retreat, the draining of a lake that had been dammed and the expansion of lakes or fjords. In the case of Greenland’s glacier that are not confined by a fjord it can be the formation of new islands. This is no longer a rare occurrence. A close look at many areas along the west coast north of Disko Island reveals a number of new islands such as for Upernavik Glacier. Another location further north where new islands are being created is Kong Oscar Island. Box and Decker (2011) note that the retreat rate of the last decade has been 0.6 square kilometer per year. Howat and Eddy(2011) Examine 75 glacier termini in NW Greenland from 2000-2010 and find an average retreat of 127 meters per year and all but two are retreating. They further note that this contrasts to the retreat rate for the same area of 17-20 meters per year. Landsat images for the Kong Oscar Glacier region from 2002, 2010 and 2011 are below. The terminus of the southern most terminus shown, Sverdrup Glacier, is outlined and is near the tip of an island in 2002 and by 2011 Sverdrup Glacier has retreated 4 kilometers in this eight year period, note yellow arrow. Three islands are examined all noted by red arrows and lettered A-C, these islands are all part of Nansen’s or Nordesnkiolds Glacier. Island A was connected to the ice sheet in 2002 and now is separated by a deep water passage. Island B is just hanging on in 2011, compared to 2002 and even 2010. This connection will likely not survive next summer. The same can be said for Island C. . This glacier is not confined to a narrow front or a single terminus in a fjord. The rate of retreat may be less, but the overall area lost is not. We must note that there are many new islands being formed it is not just a single island somewhere, such as Warming Island.