Madaket, MA Coastal Erosion Rate
Is the coast eroding 1.8 miles west of Madaket, MA?
USGS's shoreline-change data puts this stretch, 1.8 miles west of Madaket, MA, at 3.67 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 36.7 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 Madaket, MA, rather than showing one arbitrary line. Segment center: 41.28, -70.22. The survey behind it runs to 2007-2009, in USGS's New England / Mid-Atlantic assessment, using the LRR method. Shoreline surveys aren't repeated every year, so this is the most recent long-term measurement USGS has published for this coast, not a live reading.
What 3.67 ft/yr means over time
Run 1.8 miles west of Madaket, MA's 3.67 ft/yr rate forward 25 years and it implies about 92 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
28 transects feed this segment's number; 100% of them individually measured retreat. The published margin on this reading runs ±0.8 ft/yr. Among the 1211 US coastal segments with a measurable trend, this one ranks 76 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS Open-File Report 2010-1119. For scale: Gloucester, MA, 93 miles away, ranks 522 of 1211 nationally for erosion, 0.18 ft/yr, a small fraction of this stretch's own rate. 1.4 miles up the coast, Madaket, MA shows 3.49 ft/yr of eroding.
Madaket, MA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.