Rapid sea-level rise in the Gulf of Maine, USA, since AD 1800

Two sea-level records from salt marshes in coastal Maine are derived from foraminiferal analyses and AAIS C-14, Pb-210, Cs-137 and pollen chronology, Both records cover the period from AD 800 until the present and show corresponding patterns of sea-level change when corrected for trends which could accommodate millennial-scale isostatic adjustments. The records provide a detailed sea-level chronology for the last few centuries and thus link the instrumental (tide-gauge) record with the long-term geological record of sea-level change. Results show that sea level was relatively stable between AD 800 and 1300 and reached a lowstand around AD 1800, which was preceded by an oscillation in the eighteenth century. Since AD 1800, sea levels in the Gulf of Maine have risen by 0.3-0.4 m. The onset of this rise corresponds with regional climatic warming and could be interpreted as thermal expansion of the Gulf of Maine and North Atlantic sea surface. Sea-level rise possibly slowed temporarily during the mid-nineteenth century, but twentieth-century rates are unprecedented in the last millennium and correspond with hemispheric warming.