Siasconset, MA Coastal Erosion Rate
Shoreline change 2.9 miles north of Siasconset, MA
The coast 2.9 miles north of Siasconset, MA has been retreating at a measured 0.48 feet a year, USGS's own long-term rate for this stretch, built from historical shoreline positions rather than a single survey. At that rate, the shoreline has lost roughly 4.8 feet over the last decade.
What "Siasconset" means on this page
This is a roughly 3.5-mile stretch of coast, not one address or parcel - USGS's own transects run every few hundred feet, but that's finer than any one property needs, so this page reports the stretch nearest Siasconset, MA. Centered near 41.31°N, 69.99°W. Survey years: 2007-2009, method LRR, from USGS's New England / Mid-Atlantic shoreline-change assessment. That's how current the data is here, real, but not a live feed, since a shoreline survey is a major undertaking, not an annual check-in.
25 years at this rate
If 0.48 ft/yr holds for the next 25 years, the coast 2.9 miles north of Siasconset, MA would retreat roughly 12 more feet, a projection, not a certainty: erosion rates shift with storms, sediment supply and any armoring built in the meantime.
Where this fits nationally
This reading comes from 93 individual transects averaged together, 100% of which measured erosion rather than growth. USGS's confidence interval here is ±0.29 ft/yr. This segment ranks 302 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2010-1119. For scale: Greenbackville, VA, 361 miles away, ranks 322 of 1211 nationally for erosion, 0.45 ft/yr, 0.9x this stretch's rate. 1.9 miles away, Siasconset, MA is the nearest other measured stretch: also no significant trend.
Not this whole stretch, just Siasconset itself: the Coastal Change Hazards Portal is USGS's own live version of this data.