March 10, 2013
At the south end of Dexterity Fjord on the northeast coast of Baffin Island is an unnamed icecap that I will refer to as Dexterity Icecap. Gardner et al (2012). Gardner et al 2011 and Sharp et al (2011) both note that the first decade of the 21st century had the warmest temperatures of the last 50 years, the period of record. identified that the mass loss had doubled in the last decade versus the previous four for Baffin Island. Landsat images from 1990, 1994 and 2011 are used to assess the changes in this icecap. Red arrows are used to identify nunataks within the icecep, bedrock islands amidst the glacier. In 1990 and 1994 there are three evident nunataks. By 2011 there are six nunataks indicating this ice cap is thinning. In 2011 the ice cap has only 5-10% snowcover, the rest has melted away, not a good sign for an ice cap. There are a series of letters A-F on each image indicating particular locations. It is evident that the terminus has shrunk in width in particular in 2011 from the 1990’s. At Point B the glacier has receded from the edge of a small lake. At Point C a small ice cap has separated from its larger neighbor between the 1990’s and 2011. At Point D it is difficult to discern the terminus in the lake in 1990 and 1994. That the lake is open in 2011 and has numerous icebergs and the open water can absorb more heat from the sun, suggests that this terminus could suffer from enhanced melting and calving going forward. Point E represents a small tongue of ice that in the 1990’s extended to the top of gully, but by 2011 was gone. Point F indicates an ice cap that has a very tenuous connection to the Dexterity Ice Cap. It is the width of the ice cap that has diminished the most from 800-900 meters in the 1990’s to 500-600 m in 2011. The retreat of Dexterity Ice Cap is similar to that of Penny Ice Cap further south on Baffin Island and Devon Ice Cap further north in the Canadian Arctic. A paper out this past week concludes that there is an ongoing irreversible mass loss of glaciers in the Canadian Arctic Lenearts et al (2013).