MODERN MICROFOSSIL DISTRIBUTIONS OF THE OUTER BANKS, NORTH CAROLINA AND THE DEVELOPMENT OF A TRANSFER FUNCTION TO RECONSTRUCT FORMER SEA LEVELS

Concerns surrounding accelerations in the rate of sea-level rise have focused attention on linking short-term instrumental and satellite records with longer-term geologically based reconstructions of relative sea level (RSL). An ultimate goal of this research is the development of new records with sufficient resolution to detect low-magnitude variability but long enough duration to reliably establish climate-ocean relationships and secular trends. The microfossil transfer function approach is a new technique which is effective in establishing these kinds of records. We collected modern foraminiferal and diatom data from the Outer Banks, North Carolina, which have different salinity regimes due to their varying distances from a major barrier island inlet. We developed a multi-proxy transfer function to reconstruct former RSL based upon the relationship between microfossil assemblages and elevation. Results imply that this is possible to a precision of ± 0.08m. The transfer function is used to construct a RSL curve from fossil assemblages from Salvo, Buxton and Sand Point, North Carolina. These results suggest a sea-level rise of 0.70m sea-level rise over the last c. 150 years, at an average of c. 3.7 mm yr-1. This is consistent with existing sea-level data, and illustrates the utility of the transfer function approach.