Groundwater near coastlines can become salty, affecting its usability. Over time, this saltwater intrusion has spread deeper underground. Recent studies show that the interface between saltwater and freshwater can lead to submarine groundwater discharge. This discharge can even occur in the deep sea. Researchers have found that groundwater flow is influenced by this interface, shaping its movement. By studying submarine groundwater discharge and simulating groundwater flow, scientists have gained a better understanding of how saltwater and freshwater interact underground.