Atlantic coast of the United States

Atlantic coast of the United States

The Holocene sea-level database for the Atlantic coast of the United States contains 492 index points, which locate the position of relative sea level (RSL) in time and space, and 344 limiting dates, which constrain the minimum or maximum limit of former sea level. The majority of the index points in the database are from 6 ka BP to present, with only 7% older than 6 ka BP. Spatially, index points are distributed between Maine and South Carolina, but there is an absence of data from Georgia and the Atlantic coast of Florida.

The database is sub-divided into 16 regions based on the distance from the Laurentide Ice Sheet and are classified depending upon their susceptibility to compaction. The index points and limiting data demonstrate that RSL did not exceed present (0 m) during the Holocene except in regions 1 and 2 (Eastern Maine and Southern Maine, where a sea-level low stand indicates that RSL dropped from above present prior to 9 ka BP. Rates of RSL change were highest during the early Holocene and have decreased over time, due to the diminishing response of the Earth’s mantle to glacial isostatic adjustment and reduction of ice equivalent meltwater input.