A preindustrial sea-level rise hotspot along the Atlantic Coast of North America

Abstract

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.