Honors College Theses

Publication Date



Geology (B.S.)

Document Type and Release Option

Thesis (restricted to Georgia Southern)

Faculty Mentor

Dr. Jacque Kelly


Submarine groundwater discharge (SGD) is a proven source of many vital nutrients for marine and terrestrial ecosystems and has been shown to vary spatially and temporally. Variations of SGD in environments like the Spartina alterniflora dominated salt marsh near St. Simons Island, GA is an area in need of further study. The objective of this study is to quantify seasonal variation of SGD in a salt marsh estuary, using continuous radon surveys and marine electrical resistivity (ER) tomography surveys. I hypothesize that total SGD will be the greatest several months after the rainy season (June – September). We conducted three continuous radon surveys to measure SGD fluxes from the creek bank and two ER surveys to locate SGD from the creek bed. Total discharge of the study site was greatest in October. The ER data showed highest Ohm-m readings in October as well. Additionally, a strong correlation exists between total SGD and precipitation 2-7 months before each survey. These results produced a time frame for modeling precipitation’s effect on SGD, and show that ER and Rn surveys can be used together to provide a more accurate model of SGD.