Heterogeneity-Induced Mixing and Reaction Hot Spots Facilitate Karst Propagation in Coastal Aquifers

The freshwater-seawater mixing zone is a critical region for chemical activity. Yet little is known about the influence of ever present spatial heterogeneity on the dynamics of mixing and calcite dissolution, which play a key role in the understanding of karst development. We analyze the impact of different heterogeneity structures and strengths on the local and global response of mixing and dissolution rates across the saltwater freshwater mixing zone. We find that the initial heterogeneity structure significantly impacts observed dissolution and mixing patterns, which sheds some new light on karst propagation in coastal aquifers. y