Landscapes Where Ice and Sediment Meet

Irina Overeem investigates how erosion and sediment transport operate in glacier and permafrost landscapes. Work around Alaska’s Juneau Icefield combines glacier modelling, lake bathymetry, frontal surveys and sediment sampling to test estimates of transport by thinning, retreating glaciers and deposition in proglacial lakes. A second case examines Arctic river sediment fluxes, including observations of thunderstorms and thermal bank erosion along the Canning River. Machine learning applied to remote sensing extends the analysis across the Arctic, indicating that smaller rivers contribute about 117 ± 13 million tonnes of sediment per year, approximately 36% of the combined permafrost-river total. Suspended sediment concentrations increased in roughly 40% of studied continuous-permafrost river reaches over 36 years. The talk evaluates links to bank erosion and abrupt thaw and considers how field measurements, process models and automated change detection can improve predictions of geomorphic responses to warming.