INTERACTIONS BETWEEN EMBAYMENT PHYSIOGRAPHY AND CLIMATE VARIABILITY IN THE 20TH CENTURY RECORDED IN THE SEDIMENTS OF SALT MARSHES FROM LONG ISLAND, NY, USA

Salt marshes in varied physiographic environments are shown to respond rapidly to climate variability, though the exact response depends strongly on the local physiography. Salt marsh accretion rate geochronologies from four embayments in Long Island, NY, U.S.A., were determined using the naturally occurring radioisotope, Pb-210. These geochronologies were correlated to local climate proxies, including the Battery Park tide gauge and the NAO index. Salt marsh accretion rates track changes in the tide gauge record on time scales of 2-5 years, which is a closer coupling than reported in many previous studies. Accretion rates in an upper meso-tidal, low- fetch setting correlated with the position of annual mean sea level. In environments with lower tidal ranges and longer fetches changes in salt marsh accretion rates appear to track the annualized rate of mean sea-level change. This presentation will include a detailed discussion of the relationship between short-term variability in the tide gauge record and regional scale meteorological forcings. These findings suggest that the impacts of climate variability on coastal ecosystems may be as dependent on the geological surroundings as they are on the varying climatic parameters.