Presentation Type
Poster
Full Name of Faculty Mentor
Rich Viso, Marine Science
Major
Marine Science
Presentation Abstract
Saltmarsh hydrogeology can be characterized as exceptionally dynamic, with a diversity of pore water salinities, sediment porosities, and varied hydrologic inputs and outputs such as groundwater, precipitation, and tidal cycles. Of the studies done in these systems, much attention has been focused on the low marsh with regard to tidal pumping and the consequent horizontal pressure gradients which affect the subsurface hydraulic head. Perhaps, an equally dynamic boundary is expected at the groundwater interface of the barrier island and high marsh. Here, electrical resistivity tomograms were generated in a back-barrier, high-marsh site landward of Waties Island, South Carolina. Co-located transects of 112 meters and 17 meters in length provided maximum depth penetration (30 m) and best possible shallow resolution, respectively. The electrical signal is sensitive to changes in lithology, porosity, and pore water chemistry. Tomograms were collected over a twelve-month timeframe in order to image sediment horizons and possible groundwater mixing between the barrier island and high marsh throughout the year. The remarkable stability of the electrical signal throughout the seasonal, meteorological, and tidal events during the study period, suggests that fresh, island-derived pore water and salty high marsh groundwater interflow consistently. Small deviation and anomalies in this signal are possible responses to increased precipitation events or increased evapotranspiration rates affecting the high marsh pore water.
Location
Poster Session 2
Start Date
13-4-2022 4:30 PM
End Date
13-4-2022 6:30 PM
Disciplines
Oceanography
Recommended Citation
Wrobel, Dean, "Investigating Temporal Groundwater Interactions between a Barrier Island and High Marsh Environment" (2022). Undergraduate Research Competition. 88.
https://digitalcommons.coastal.edu/ugrc/2022/fullconference/88
Included in
Investigating Temporal Groundwater Interactions between a Barrier Island and High Marsh Environment
Poster Session 2
Saltmarsh hydrogeology can be characterized as exceptionally dynamic, with a diversity of pore water salinities, sediment porosities, and varied hydrologic inputs and outputs such as groundwater, precipitation, and tidal cycles. Of the studies done in these systems, much attention has been focused on the low marsh with regard to tidal pumping and the consequent horizontal pressure gradients which affect the subsurface hydraulic head. Perhaps, an equally dynamic boundary is expected at the groundwater interface of the barrier island and high marsh. Here, electrical resistivity tomograms were generated in a back-barrier, high-marsh site landward of Waties Island, South Carolina. Co-located transects of 112 meters and 17 meters in length provided maximum depth penetration (30 m) and best possible shallow resolution, respectively. The electrical signal is sensitive to changes in lithology, porosity, and pore water chemistry. Tomograms were collected over a twelve-month timeframe in order to image sediment horizons and possible groundwater mixing between the barrier island and high marsh throughout the year. The remarkable stability of the electrical signal throughout the seasonal, meteorological, and tidal events during the study period, suggests that fresh, island-derived pore water and salty high marsh groundwater interflow consistently. Small deviation and anomalies in this signal are possible responses to increased precipitation events or increased evapotranspiration rates affecting the high marsh pore water.