Description
Submarine groundwater discharge (SGD) and offshore freshened groundwater (OFG) are two interdependent aspects of coastal groundwater systems that have important effects on water security, freshwater budgets, and sustainable water management. OFG, defined as low-salinity groundwater stored within sediments beneath the seabed, has been identified on many passive continental margins worldwide and has been recognized as a potential unconventional freshwater resource. Conversely, SGD constitutes a key pathway for the release of nutrients and contaminants from the seabed into the coastal water column, influencing coastal biogeochemical cycles and marine water quality.
Understanding the distribution and dynamics of OFG and SGD requires a multidisciplinary approach that integrates geophysical surveys, drilling and sedimentological characterization, hydrogeochemical analyses, numerical modeling, and emerging tools such as remote sensing and artificial intelligence. However, both OFG and SGD investigations face significant challenges related to limited accessibility, sparse observational data, and the need for integrated hydrological, geological, and marine datasets. This session invites contributions that address the detection, characterization, and modelling of offshore and coastal groundwater systems, including site-specific case studies, methodological developments, and integrated modelling frameworks that link terrestrial groundwater, offshore aquifers, and coastal seas. We welcome studies on past and present emplacement of OFG, future evolution under climate change and sea-level rise, and the role of SGD in transporting freshwater and solutes to the ocean. Contributions focusing on data integration, innovative monitoring approaches, and management perspectives are particularly encouraged, especially in vulnerable coastal regions where water scarcity, pollution, and anthropogenic pressures are critical concerns.