Fig. 8: Comparison of the satellite image (Sentinel2) of the high-altitude Blue Ice Area in Jutulsessen with its complete digitized twin.

a: Sentinel2 image of the BIA (source: Quantarctica59), blue rectangle was selected for a closeup presented in b; b: a close-up of the ice surface showing cryoconite holes extracted from a high-resolution satellite image taken in November 2019 (World View Stereo © 2013 – 2017 DigitalGlobe, Maxar Technologies); c: digitized version of a; created in QGiS with Semi-automatic classification plugin. Cryoconite holes in the digitized version are visible as dark blue dots. Areas with white outline represent Zones with distinct concentration of the holes; d: The close-up of the rectangle in c.