Quantifying salinity in the layered coastal aquifers underlying and adjacent to Delaware Bay USA using AEM-derived resistivity

Airborne electromagnetic (AEM) methods are particularly well suited to coastal aquifer salinity studies, yet the quantitative translation from bulk resistivity to fluid salinity carries uncertainty that can impact mapped salinity distributions and interpretations of the freshwater-saline interface and hydrostratigraphic layers. A recent AEM survey of the region near the Delaware Bay, USA highlights several challenges common to coastal hydrogeologic settings that may influence both qualitative and quantitative interpretation. We use a Bayesian inversion to estimate geophysical parameter uncertainty, and results are integrated with hydrogeologic measurements to develop quantitative interpretations of salinity across the freshwater-saline interface in stacked aquifers.