Onset of recent rapid sea-level rise in the western Atlantic Ocean

A high-resolution record of sea-level change spanning the past 1000 years is derived from foraminiferal and chronological analyses of a 2 m thick salt-marsh peat sequence at Chezzetcook, Nova Scotia, Canada. Former mean tide level positions are reconstructed with a precision of ±0.055 m using a transfer function derived from distributions of modern salt-marsh foraminifera. Our age model for the core section older than 300 years is based on 19 AMS 14C ages and takes into account the individual probability distributions of calibrated radiocarbon ages. The past 300 years is dated by pollen and the isotopes 206Pb, 207Pb, 210Pb, 137Cs and 241Am.Between AD 1000 and AD 1800, relative sea level rose at a mean rate of 17 cm per century. Apparent pre-industrial rises of sea level dated at AD 1500–1550 and AD 1700–1800 cannot be clearly distinguished when radiocarbon age errors are taken into account. Furthermore, they may be an artefact of fluctuations in atmospheric 14C production. In the 19th century sea level rose at a mean rate of 1.6 mm/yr. Between AD 1900 and AD 1920, sea-level rise accelerated to the modern mean rate of 3.2 mm/yr. This acceleration corresponds in time with global temperature rise and may therefore be associated with recent global warming.