Gloucester, MA Coastal Erosion Rate
Is the coast eroding 3.2 miles south of Gloucester, MA?
Good news, and an honest one: USGS's data can't distinguish this stretch, 3.2 miles south of Gloucester, MA, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
What "Gloucester" means on this page
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 Gloucester, MA, rather than showing one arbitrary line. Segment center: 42.59, -70.71. 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.
Where this fits nationally
This reading comes from 31 individual transects averaged together, 71% of which measured erosion rather than growth. USGS's confidence interval here is ±0.12 ft/yr. The unadjusted figure here, -0.05 ft/yr, would place it 709 of 1211 if ranked directly - but an unreliable rank isn't a useful one, which is exactly why "no significant trend" is the headline instead. Source: USGS Open-File Report 2010-1119. Smith River, CA sits at national rank 919 for growth (0.19 ft/yr), one reference point among the 1211 scored segments, 2688 miles from here. Gloucester, MA, 1.3 miles off, is the adjacent measured stretch, reading slight erosion at 0.18 ft/yr.
Gloucester, MA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.