Gravity Derived Bathymetry Beneath a Section of the Ronne Ice Shelf Downstream of the Evans Ice Stream, West Antarctica, and Implications for Ice Shelf Stability

Ice shelves exert a buttressing effect on the Antarctic ice sheets that can reduce as basal melting drives their thinning and destabilization. This process is strongly affected by the depths and morphologies of the underlying cavity floors, which regulate ice-ocean interactions, but remain poorly constrained. We created a new model of the bathymetry beneath a section of the Ronne Ice Shelf downstream of the Evans Ice Stream by inversion of carefully selected airborne gravity data constrained by seismic and ice-penetrating radar depth references. The model reveals a deep, asymmetric and U-shaped trough aligned with the ice flow direction, reflecting glacial erosion and tectonic inheritance. The persistent retrograde slope of the seafloor potentially allows warm water intrusion from the open ocean up to the grounding line. Our model thus provides critical constraints for estimating basal melt rates and assessing ice shelf and ice sheet stability with regard to large-scale climate changes.