Schweppe Seminar

The field of submarine groundwater discharge (SGD) was launched in the 1990s by the remarkable discovery, via naturally-occurring isotope tracers, that saline groundwater was discharging to the South Atlantic Bight in very large volumes. Subsequent studies confirmed that saline groundwater discharges to the Atlantic Ocean in volumes that rival river discharge, with similarly large nutrient contributions. These findings were slow to find widespread acceptance, however, because this discharge has not been observed near the shoreline, and no conceptual models for SGD farther from shore existed. We now have five years of heat tracer evidence for large pulses of groundwater discharge occurring 10-15 km offshore in the South Atlantic Bight, in volumes consistent with 65-70% of the Ra observed in the region. Additional Ra tracer evidence suggests discharge as far as 80 km offshore. New geochemical analyses confirm major nutrient contributions by these pulses of SGD. This talk investigates this 20-year mystery and the recent discoveries that suggest that it may be time to rewrite chemical budgets for the coastal ocean.

Biography

Alicia Wilson is a professor of hydrogeology in the School of the School of the Earth, Ocean, and Environment at the University of South Carolina, with graduate degrees from Stanford University (MS) and Johns Hopkins University (PhD). She specializes in coastal hydrogeology, with a particular focus on coastal ecohydrology and submarine groundwater exchange. A fellow of the Geological Society of America, Wilson is a past chair of the GSA Hydrogeology Division and served as the Director of the School of the Earth, Ocean, and Environment at UofSC before becoming the 2023 Darcy Lecturer for the National Ground Water Association.