Sea level rise in Wellfleet, MA is predominantly a combination of rising ocean waters and land subsidence. Changes in sediment transport within the harbor may also affect relative sea level rise, by changing the amount of sand deposited on the bottom in different locations. An additional factor that may increase sea level rise in the northeastern US compared to other parts of the globe is the slowing of ocean currents.
In the northeastern US the combination of rising ocean waters and land subsidence is leading to higher relative sea level rise compared to many other coastlines in the US and elsewhere. Since 1900 the rate of sea level rise in the northeast has exceeded the global average by approximately 4 inches to about 1 foot in the Northeast versus about 8 inches globally over the past 110 years. The most recent assessments project a global sea level rise of 1-4 feet by 2100, with the northeast continuing to exceed global averages.