September 3, 2019

Hutchinson Glacier, Greenland Releases New Island

Posted by Mauri Pelto

Cape Deichmann becomes an island as it disconnects from Hutchinson Glacier. Landsat images from 2010 and 2019.

The Hutchinson (H) and Polaric Glacier (P) region of East Greenland indicating three locations of island forming or about to form in 2010 and 2019 Landsat images.  Point #1 is Flado Island, Point #2 and Point #3 is Cape Deichmann

Ziaja and Ostafin (2019)  noted the formation of a new island at Cape Deichmann (3) due to recession of Hutchinson Glacier (H). Here we use Landsat images from 2010-2019 to examine the release of this island and other islands and pinning points  in the Hutchinson and Polaric Glacier area. This is one of a growing number of examples of glacier retreat leading to island formation.

In 2010 a tongue of Hutchinson Glacier connects to Cape Deichmann.  Hutchinson Glacier also connects to five other islands along its front, helping provide stability to the ice front.  Pinning points such as these islands reduce calving directly (Hill et al 2017), but also suggest limited water depth, which would reduce the impact of warm ocean water.  The center of Polaric Glacier also has Island #2 that provides stability.  At Flado Island (#1) the west margin of Polaric Glacier does not reach this island, but a melange of ice fills the space between the glacier front and the island, which does provide a degree of stability (Moon et al 2015). In 2012 there is no change in the Cape Deichmann or at Island #2.  Flado Island has lost its melange during this summer of exceptional warmth, but an ice tongue still reaches to within 1 km of the island.  In 2015 there is no change at Cape Deichmann or at Island #2.  The gap between the Polaric Glacier front and Flado Island is filled by a melange again.  In 2019 the Hutchinson Glacier ice tongue to Cape Deichmann is gone.  The ice front is now 0.6 km from the now Deichmann Island.  Island #2 is still embedded in the Polaric Glacier front.  Flado Island  has lost its melange in the warm summer of 2019, the central ice front of Polaric Glacier has also retreated 1.5 km, while the east and west margins changed little.  This will make it more difficult to develop a persistent melange of ice between the glacier front and Flado Island. There will be new island formed in the near future in this region.

The Hutchinson (H) and Polaric Glacier (P) region of East Greenland indicating three locations of island forming or about to form in 2010 and 2019 Landsat images.  Point #1 is Flado Island, Point #2 and Point #3 is Cape Deichmann

Flado Island with the removal of the melange in front of Polaric Glacier and the retreat of the glacier front from 2010-2019.

Map of the Hutchinson Glacier terminus region.