Interactions of wind-transported snow with a rift in the Ross Ice Shelf, Antarctica

Rifts in ice shelves accumulate a melange of snow and firn from above and marine ice from below, material that has been postulated to negatively influence iceberg calving. From measurements and modeling we show that a 100 m wide rift near the front of the Ross Ice Shelf captures all wind-transported snow traveling in saltation and a substantial fraction of the snow blowing in suspension across the rift. Moderate winds and snow transport appear sufficient to fill the rift in several years, whereas the melange surface profile remains relatively constant within the 30 m deep rift. Observed subsidence and ocean temperatures in the rift suggest that net basal melting dissolves the melange from below, limiting its effectiveness as an anti-calving agent near ice fronts.