Over the last century, relative sea-level rise rates along the Atlantic coast of the U.S. have ranged between 1.8 mm/yr (Maine) to as much as 4.4 mm/yr (Virginia, Table 1; Zervas, 2001). The lowest rates (~1.8 mm/yr) are nearly equivalent to the average global rate for the 20^th century of 1.7 ± 0.5 mm/yr (Bindoff and others, 2007) and occur along coastal New England and from Georgia to southern Florida. The highest rates have been observed in the mid-Atlantic region between northern New Jersey and northeastern North Carolina (Table 1; Zervas, 2004). Subsidence of the land surface due to a range of factors contributes to the high rates of relative sea-level rise observed in this region. It is believed that the subsidence is attributable mainly to glacio-isostatic adjustments of the earth's crust in response to the melting of the Laurentide ice sheet, and to the compaction of sediments due to freshwater withdrawal from coastal aquifers (Gornitz and Lebedeff, 1987; Emery and Aubrey, 1991; Peltier, 2001).

Table 1. Rates of Relative Sea-Level Rise for Selected Long-Term Tide Gauges on the East Coast of the United States (Zervas, 2001).