A Preindustrial Sea-Level Rise Hotspot Along the Atlantic Coast of North America

The Atlantic coast of North America north of Cape Hatteras has been proposed as a "hotspot" of late 20th century sea-level rise. Here we test, using salt-marsh proxy sea-level records, if this coast experienced enhanced sea-level rise over earlier multidecadal-centennial periods. While we find in agreement with previous studies that 20th century rates of sea-level change were higher compared to rates during preceding centuries, rates of 18th century sea-level rise were only slightly lower, suggesting that the "hotspot" is a reoccurring feature for at least three centuries. Proxy sea-level records from North America (Iceland) are negatively (positively) correlated with centennial changes in the North Atlantic Oscillation. They are consistent with sea-level "fingerprints" of Arctic ice melt, and we therefore hypothesize that sea-level fluctuations are related to changes in Arctic land-ice mass. Predictions of future sea-level rise should take into account these long-term fluctuating rates of natural sea-level change.