Global sea level rise and glacial isostatic adjustment: An analysis of data from the east coast of North America

The fact that modern rates of secular sea level change recorded on tide gauges are significantly contaminated by the ongoing influence of glacial isostatic adjustment is now well known (Peltier 1986, 1988, Peltier and Tushingham 1989). The east coast of the continental United States is uniquely monitored both by a dense network of such tide gauge installations and by a similarly dense coverage of C-14 dated relative sea level histories extending several millennia into the past. In this letter we employ the latter data, which primarily record the glacial isostatic submergence of this coast, to ''decontaminate'' the tide gauge records of this influence. The, perhaps climate related, signal so revealed is much more uniform spatially than either of the individual data sets and when averaged along the coast, yields a rate of relative sea level rise of 1.94 +/- 0.6 mm yr(-1). Furthermore, comparisons of the C-14 data from along the coast with the predictions of global models of the glacial isostatic adjustment process are shown to provide key insights into the design of a ''best'' theoretical model that may be employed for ''decontamination'' of the global tide gauge data set to more clearly reveal the climate related signal.