Antarctic ice shelves are losing mass at increasing rates, yet the ice-ocean interactions that cause significant ice loss are not well understood. A new approach of high-resolution phase-change simulations is used to model vertical ice melting into a stratified ocean. The ocean dynamics show complicated interplay between a turbulent buoyant meltwater plume and double-diffusive layers, while the ice actively melts and changes topography. At room temperatures, the double-diffusive layer thickness is closely linked to ice scalloping. At lower, more realistic ocean temperatures, the meltwater plume becomes prominent with a laminar-to-turbulent transition imprinting an indent on the melting ice. The double-diffusive layer thickness is consistent with scaling prediction, while the real-world application demonstrates reasonably good matching of the scaling prediction for some Antarctic regions. Our study is a key first step toward the future use of high-resolution phase-change fluid dynamics simulations to better understand Antarctic ice shelves in a changing climate.