Sagamore, MA Coastal Erosion Rate
Shoreline change 1.4 miles northwest of Sagamore, MA
USGS's shoreline-change data puts this stretch, 1.4 miles northwest of Sagamore, MA, at 0.27 feet of erosion a year on average, a long-term rate for this specific ~3.5-mile section, not one storm's damage. At that rate, the shoreline has lost roughly 2.7 feet over the last decade.
The grain of this number
USGS surveys the coast in transects spaced a few hundred feet apart; this page groups the nearest ones into a single ~3.5-mile reading for the stretch closest to Sagamore, MA, rather than showing one arbitrary line. Segment center: 41.80, -70.54. USGS's New England / Mid-Atlantic assessment last surveyed this stretch through 2007-2009, computing the rate with its LRR method. Other US regions were surveyed in different years, sometimes decades apart, so this page states its own rather than implying one national vintage.
What 0.27 ft/yr means over time
Run 1.4 miles northwest of Sagamore, MA's 0.27 ft/yr rate forward 25 years and it implies about 7 feet of further retreat, assuming nothing changes, which is exactly the assumption a seawall or nourishment project exists to break.
What backs this reading up
Averaging 91 separate transects produced this segment's rate, with 96% individually reading as erosion, rather than relying on any single survey line. USGS's confidence interval here is ±0.15 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 420 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS Open-File Report 2010-1119. Rank 364 nationally for erosion belongs to Sagaponack, NY, 110 miles from this stretch, measured at 0.37 ft/yr, 1.4x this stretch's rate. 2.1 miles away, Sagamore, MA is the nearest other measured stretch: also no significant trend.
Sagamore, MA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.