Icings: Their Structure and Influence on the Hydrological Network of a Small Arctic Glacier Forefield

ABSTRACT We address the evolution of a proglacial hydrographic network under the influence of icings over a small Arctic glacier forefield in the context of glacier retreat. The newly deglaciated area allows glacial rivers to carve new channels as fine‐grained sediment is exposed. The main glacier outlet flow from one channel to another is controlled by icings over the years. The research methodology involves analyzing optical camera images for qualitative observations of morphological evolutions and LiDAR data for quantitative estimates of the icings' volume as well as riverbed profiles. Ground penetrating radar (GPR) is used to investigate the internal structure of icings and its possible influence on runoff streams. Based on the seasonal persistence of icings and their spatial extent, we observe that icings act as dams channelling the main glacier outlet between canyons carved in the deglaciated areas and, when lasting long enough, even define long‐term outflow paths. The internal structure of icings suggests that upstream, deep icings are permeable to water flow while downstream dense, shallow icings act as watertight obstacles, contributing to their dam effect.