Prof. Dr. Willard S. Moore 

The project is part of the "The Dynamic Deep Subsurface of High Energy Beaches (DynaDeep) research group working on Spiekeroog Island to evaluate the impact of freshwater seawater mixing in this dynamic system on the chemistry of the coastal sea.The beaches found on barrier islands, like Spiekeroog, are the site where freshwater flowing off the land and infiltrating saltwater mix, similar to surface river mouths. Like rivers, the fresh groundwater is the carrier of a range of dissolved and particulate chemicals that include reservoirs of nutrients and organic carbon that affect the chemistry of the coastal ocean. The zone in the sand where the freshwater and saltwater meet and mix is the site of intense chemical reactions that change the chemical composition of the dissolved components of the waters. These reactions play a significant role in the overall organic carbon and nutrient cycles as they mediate their net exchange between the land and the sea. This proposed work will use naturally occurring radionuclides as tracers of the rate of exchange of the groundwater between the land and sea. This work in conjunction with other work in the DynaDeep project will support a better understanding of the impact of mixing zone reactions in high energy beaches on the carbon and nutrient dynamics in the coastal ocean.