Autonomous Large-Scale Radon Mapping and Buoyant Plume Modeling Quantify Deep Submarine Groundwater Discharge: A Novel Approach Based on a Self-Sufficient Open Ocean Vehicle

• DOI: 10.1021/acs.est.3c00786
• Publication Date: 2023-04-17T13:36:05Z
• Authors: Thomas Müller; Jonas Gros; Patrick Leibold; Hajar Al-Balushi; Eric Petermann; Mark Schmidt; Warner Brückmann; Mohammed Al Kindi; Omar S. Al-Abri
• Keywords: Submarine groundwater discharge; Seafloor Spreading; Groundwater discharge; TRACER; Outflow

Groundwater discharge into the sea occurs along many coastlines around world in different geological settings and constitutes an important component of global water matter budget. Estimates how much flows worldwide vary widely are largely based on onshore studies hydrological or hydrogeological modeling. In this study, we propose approach to quantify a deep submarine groundwater outflow from seafloor by using autonomously measured ocean surface data, i.e., 222Rn as tracer, combination with numerical modeling plume transport. The model field data suggest that outflows depth ∼100 m can reach implying several cubic meters per second freshwater discharged sea. We postulate extreme rainfall event 6 months earlier likely trigger for discharge. This study shows measurements at surface, which easier conduct than seafloor, be used not only localize discharges but, modeling, also estimate magnitude release flow rate.