Southeast #3 Glacier, Devon Ice Cap in July 9, 2016 and August 29, 2021 Sentinel 2 images of the lower 10 km  showing three supraglacial streams S1, S2 and S3 and the outlet plumes of each stream at Point 1-3. The yellow line is the 2016 margin.

The southeast sector of the Devon Ice Cap, Devon Island, Nunavut has three tidewater outlet glaciers Southeast Glacier #1, #2 and #3.  Van Wychen et al (2017) indicate the dynamic discharge of the three at .06-.07 Gt per year, all three glaciers have been retreating during this period.  Southeast #3 is between 0.01 and 0.02 Gt per year.  Sharp et al (2011) note that increasing summer temperatures has led to increased mass loss on Devon Ice Cap. Here we examine retreat and the supraglacial stream networks using Landsat and Sentinel 2 imagery.

In 2002 the calving front of Southeast #3  Glacier extended north from with five distinct peninsulas of ice. The retreat by 2016 was more pronounced on the north south oriented southern portion of the front than the northwestern part.  From 2016 to 2021 it is evident that the glacier front has receded, particularly at the prominent ice peninsulas evident in 2016. The retreat averages 600 m across the 5 km wide tidewater front seen above from 2016-2021. This is an addition to the  1200 m retreat from 2002-2016, while the northwestern section retreated ~500 m during the 2002-2021 period. S1, S2 and S3 indicates supraglacial stream drainages that exit the glaciers at Point 1-3 respectively.  The plumes of sediment from these streams is evident in the July 24, 2020 image below from each of these surface outlet streams. The plumes are evident in the July 2016 image, but no the late August image of 2021.  The lack of plumes on 8-29-2021 indicate the lower melt rates that are typical of late August. The stream network has become more prominent as melt rates have led to greater flow and more incising into the ice.

This retreat has occurred during the same period that was noted as generating three new islands in 2018 on the northeast margin of the Devon Ice Cap. Noel  et al (2018) observe that this is part of a trend seen across Canadian Arctic ice caps have been losing mass for decades and that mass loss accelerated in 1996.

July 24, 2020 Sentinel 2 image of the lower 10 km of Southeast #3 Glacier showing three supraglacial streams S1,S2 and S3 and the outlet plumes of each at Point 1-3.

Southeast #3 Glacier in 2002 and 2021 Landsat images. Yellow dots indicate the 2002 margin of the glacier.