Carolina Bays and their connection to natural hydrogen gas seepage in the southeastern United States

Carolina Bays are semi-circular depressional wetlands in the Atlantic Coastal Plain of the United States. By documenting matching identifications of Bays from two previously conducted large-scale mapping efforts, this study determined a conservative estimate for Carolina Bays to be ∼20,000. Carolina Bays have garnered interest due to the identification of molecular hydrogen seepage from these and other semi-circular depressional features worldwide. Hydrogen could be an important resource for carbon-free energy in the future. The potential for natural hydrogen within Carolina Bays needs further exploration to determine the degree of hydrogen availability.

In this study, screening methods for molecular hydrogen gas within Georgia and the Carolinas were conducted utilizing surface and soil gas measuring techniques. Molecular hydrogen was measured within and around Carolina Bays in the three regions surveyed, confirming a likely link between these structures and molecular hydrogen seepage. Minor variations in surveying techniques led to shifts in the magnitude of hydrogen gas measurements, highlighting the importance of standardized surveying practices. Surface molecular hydrogen measurements may hold value in initial hydrogen screening for a general region. However, the lack of correlation between surface and soil gas measurements at a particular boring location limits direct comparison. The source of hydrogen gas from the Carolina Bays is unclear and needs further study. The East Coast Magnetic Anomaly and mafic dikes as geologic source rocks, as well as the role of microbial production in the soil of Carolina Bays, hold some merit.