Vineyard Haven, MA Coastal Erosion Rate
Shoreline change 8.9 miles southwest of Vineyard Haven, MA
Averaged across every transect USGS ran 8.9 miles southwest of Vineyard Haven, MA, the shoreline has been moving inland at 1.6 feet a year, a real measured rate, not a regional estimate applied to this stretch. At that rate, the shoreline has lost roughly 16 feet over the last decade.
The grain of this number
Vineyard Haven, MA is the nearest named place, 8.9 miles away, to a ~3.5-mile stretch of coast USGS has surveyed - the reading below covers that whole stretch, not a single property in it. Segment center: 41.35, -70.70. 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 1.6 ft/yr means over time
Run 8.9 miles southwest of Vineyard Haven, MA's 1.6 ft/yr rate forward 25 years and it implies about 40 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 82 separate transects produced this segment's rate, with 100% individually reading as erosion, rather than relying on any single survey line. USGS's confidence interval here is ±0.47 ft/yr. This segment ranks 152 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS Open-File Report 2010-1119. Rank 137 nationally for erosion belongs to Port Mansfield, TX, 1825 miles from this stretch, measured at 1.99 ft/yr, 1.2x this stretch's rate. Vineyard Haven, MA, 2.5 miles off, is the adjacent measured stretch, reading slight erosion at 0.9 ft/yr.
Vineyard Haven, MA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.