INVESTIGATING BARRIER ISLAND EVOLUTION THROUGH SEDIMENT CORE ANALYSIS AND GEOPHYSICAL SURVEYS

The geologic framework of barrier island systems affects short- and long-term island resiliency by controlling alongshore patterns in beach and dune morphology. Rapid post-storm assessment and predicting future change requires a more comprehensive understanding of the framework geology beneath modern barrier islands. To validate our understanding of the framework geology, electromagnetic inductance (EMI) and ground penetrating radar (GPR) surveys were collected along Padre Island National Seashore (PAIS), Texas, USA in 2014 through 2016. Previous studies have demonstrated that the geologic framework of PAIS is dominated by relict paleo-channels incised during the Pleistocene and later infilled by Holocene sands. The GPR and EMI surveys presented here correlate with previous studies to confirm the location of relict paleo-channels along PAIS. The next step of this investigation is gathering sediment cores along the previously surveyed GPR/EMI transects to ground-truth the geophysical surveys and refine the geochronological evolution of PAIS. Validating the geophysical data will help inform the National Park Service about how to effectively manage coastal resources in the short- and long-term. The long-term goal of this project is to develop a more comprehensive model of barrier island change by integrating framework geology into contemporary morphodynamic models.