A numerical model was used to simulate water levels, currents, waves, suspended sediment and salinity distributions in Pamlico Sound, a large and shallow back-barrier estuary in eastern North Carolina, for four distinct time slices during its geomorphic evolution over the late Holocene. Present-day bathymetry was obtained from a high resolution digital elevation model of Pamlico Sound, and paleobathymetric model grids were created for 500, 1000 and 4000 calibrated years before present (cal yr BP) using age-depth relationships developed from sediment core and time-constrained seismic observations. Hydrodynamic and sediment model results for a one-month simulation at the 0 and 4000 cal yr BP time slices are compared to assess the impacts of varying degrees of barrier island segmentation, long-term changes in basin geomorphology, and sea-level rise on the flow and transport response in Pamlico Sound.
In order to evaluate the accuracy and regional significance of salt-marsh reconstructions of former sea level based on foraminiferal transfer functions, we have calibrated the foraminiferal assemblages of a saltmarsh core from the Urdaibai estuary using the regional transfer function constructed previously for the southern Bay of Biscay. The foraminifera-based reconstructions were placed into a temporal framework
using Pb-210, heavy metal concentrations, and Cs-137-derived sediment accumulation rates. The resulting relative sea-level curve has been compared with the nearest tide-gauge data (Santander) and with other geological records from regional salt-marshes. Relative sea-level trends from core sediments support in all
cases the idea of accelerating sea levels over the last century when compared to previous centuries, providing a regional relative sea-level rise of 2.0 mm yr-1 for the 20th century.