LATE HOLOCENE RELATIVE SEA-LEVEL CHANGE ON THE EASTERN SEABOARD OF THE USA

High quality relative sea-level (RSL) data reveal spatial and temporal variations in crustal movements over the late Holocene. Current concerns regarding the potential eustatic sea-level rise associated with anthropogenic warming of the atmosphere and oceans and its impacts on coastal resources have resulted in increased interest in former RSL fluctuations. Reconstructions through the Holocene allow modellers to quantify lithospheric thickness and mantle viscosity and establish lateral variations in mantle structure across the continental/oceanic margin. Reconstructions of crustal subsidence/uplift on a regional basis allow for the development of site-specific coastal management regimes to proposed rates of eustatic sea-level rise during the 21st century.

Estimates of late Holocene rates of uplift/subsidence can be calculated from relative sea-level curves as the eustatic curve is ca. zero during this time period. This late Holocene rate of land movement demonstrates the continuing response to glacio isostatic adjustment (GIA) processes. Through analysis of the eastern seaboard from Maine in the north to Florida in the South, it is possible to demonstrate differing land movements due to glacio isostatic adjustments and to elucidate absolute rates of sea-level change through comparison with geodetic and tide gauge measurements.