2026/06/09 by Paul T. Summers, Paul Summers, Alexander Robel +8 · 1 voice
Earth and Planetary Sciences · #Arctic and Antarctic ice dynamics #Cryospheric studies and observations #Geology and Paleoclimatology Research
paper · pdf · doi:10.21203/rs.3.rs-9859110/v1
openalex publication_date 2026/06/09 · openalex created_date 2026/06/10 · openalex updated_date 2026/07/14
Abstract Rapid ice loss from the Greenland Ice Sheet is responsible for roughly 20% of global sea level rise since 2002. Almost half of this loss is moderated in part by the presence of ice mélange, which influences glacial calving and melt rates. However, the seasonal to interannual drivers of ice mélange extent and collapse are poorly understood. Observations show a spread of behavior for ice mélange in different Greenland fjords, ranging from seasonal collapse each spring over a few days to perennial persistence. Here we present a new explanation of mélange seasonality and collapse using the first coupled mélange-ocean model that incorporates both high-resolution ocean circulation and dynamic granular mélange flow. In multi-year simulations, we reproduce observed seasonal variability of ice mélange and characterize the mechanism of mélange collapse. We parameterize this mélange collapse threshold and compare to observations from five fjords across Greenland. Our results show that perennial mélange, currently present at the majority of the largest glaciers in Greenland, may suddenly collapse when subjected to increased submarine melt which could drive increased calving, glacier mass loss, and sea level rise.