Buoyancy-driven dissolution of inclined blocks: Erosion rate and pattern formation

The dissolution of a body leads to density stratifications at the interfaces that drive buoyant flows. At the bottom interface, the flow destabilizes into convective solute plumes by the solutal Rayleigh-B\'enard instability. We report experiments with salt or caramel blocks dissolving in aqueous solutions. The dissolution flow controls the block dissolution rate, interacts with the topography, and dynamically shapes three-dimensional cup-like patterns. This bedform resembles those observed on cave or iceberg walls. We derive scaling laws for the receding velocity and the pattern genesis.