Degraded Permafrost In The Arctic

Permafrost is defined as rock or soil that has been at or below the freezing point of water for two or more years.  Most of it is located in high latitudes in and around the Arctic and Antarctic regions.   Permafrost covers nearly a quarter of the exposed land in the Northern Hemisphere.



Permafrost can contain many different materials including bedrock,
sediment, organic matter, water and ice. 
Because of the presence of organic matter, permafrost is potentially the
source of significant methane emissions if it thaws and the trapped biomass
begins to rot.




A recent study looked at the results of 30 years of aerial surveys and
extensive ground mapping of an area of Canada’s high Arctic polar desert known
as the Eureka Sound Lowlands.  This area
has an extremely cold climate and the permafrost there is over 1/3 of a mile
thick.  It has long been assumed that
this landscape was stable.




Research led by McGill University in Montreal has found that this is
not the case.  The increases in summer
air temperatures seen in recent years are initiating widespread changes in the
landscape.




A particular landform known as a retrogressive thaw slump that forms
when ice within permafrost melts and the land slips down is widely occurring in
the area.  The absence of vegetation and
layers of organic soil in these polar deserts make permafrost in the area
particularly vulnerable to increases in summer air temperatures.




The research indicates that despite the cold polar desert conditions
that characterize much of the high Arctic, the interaction between ice-rich
permafrost systems and climate factors is complex and the links between global
warming and permafrost degradation are not well understood.




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Widespread permafrost degradation seen in high Arctic terrain




Photo, posted August 11, 2018, courtesy of Flickr.




Earth Wise is a production of WAMC Northeast Public Radio.