In-cave Tracing to Measure Discharge in the Great Onyx Flow System, Mammoth Cave National Park, Kentucky

Jessica Williams1, Chris Groves1, and Lee Anne Bledsoe1 1Crawford Hydrology Lab, Western Kentucky University, 1906 College Heights Blvd. Bowling Green, KY 42101 Abstract Great Onyx Cave is located in Mammoth Cave National Park, and due to its nearly pristine nature, it is an incredible area to study hydrologic and geochemical processes related to landscape evolution, nutrient cycling, and landscape/atmosphere interactions associated with the global carbon cycle. Understanding this relatively pristine cave system can act as a control for researching human impacts on similar water systems. Groundwater tracing is one of the best methods available to understand flow direction and aquifer characteristics in karst drainage basins. Using both salt and dye tracer dilution methods, discharge and hydrologic connection of key in-cave monitoring locations are determined. Groundwater travel times between in- cave locations, calculated volume, and the subsurface pathway network identified are shown to better inform geochemistry research and our 3-D conceptual model of the Great Onyx Basin. Keywords karst, dye-tracing, mappin