The end of Drangajokull?

 

These are desperately sad images -- the latest satellite imagery from Apple maps. The images show a small ice cap (Drangajokull in NW Iceland) which is now so thin that the "bones" of the landscape beneath the ice are showing through.  The catchments of the various small outlet glaciers are showing through quite clearly.   This is truly shocking -- earlier images showed that there was an ice cap worthy of the name here, with an ice surface which was largely independent of sub-surface topography.  

The top image is particularly striking, showing the string of peaks that are now breaking through the ice surface as it wastes away.  We walked up to the summit on this ice cap back in 1960, when it was still in a relatively healthy state. 

I read in one of the Iceland tourist blurbs that Drangajokull is the only glacier in Iceland that is not retreating.  That does not seem to be confirmed by the satellite images!  The most recent mass balance figures (Belart et al, 2017) suggest that the ice cap had a modest negative balance in 2015 -- but the figures used in the paper are of course now a decade out of date.  And a lot seems to have changed in a decade.

https://tc.copernicus.org/articles/11/1501/2017/tc-11-1501-2017.pdf

Satellite image showing surface contours.  The whole ice cap lies beneath 900m.  It's easy to pick out the various glacier catchments.  Several nunataks already project through the ice cap surface -- and soon there will be more. 

Another indicator of the poor state of health of the ice cap is the paucity of deep crevasses which indicate activity both above and below the firn line.  This makes the ice cap a relatively safe place for tourists -- and this is reflected in the boom in "jet ski"visits by tourists in the early summer in particular..........  All very sad.  I must check and see what the current ablation rate is here -- but the ice cap surface appears to be dropping by several metres per year.

Yet another manifestation of global warming.  The small ice cap of Ok has already gone.  This one will be next. 

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There is much more information about Drangajokull in this impressive doctorate thesis by Skafti Brynjolfson:

https://core.ac.uk/download/pdf/132157379.pdf

Skafti Brynjólfsson
Dynamics and glacial history of the Drangajökull ice cap, Northwest Iceland

Thesis for the degree of Philosophiae Doctor Trondheim, September 2015
Norwegian University of Science and Technology

The core of he thesis is the collection of published papers concentrating on the ice cap and its outlet glacier catchments.