Strathmere, NJ Coastal Erosion Rate
Is the coast eroding 0.9 miles north of Strathmere, NJ?
Averaged across every transect USGS ran 0.9 miles north of Strathmere, NJ, the shoreline has been moving inland at 0.86 feet a year, a real measured rate, not a regional estimate applied to this stretch. At that rate, the shoreline has lost roughly 8.6 feet over the last decade.
The grain of this number
Strathmere, NJ is the nearest named place, 0.9 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: 39.21, -74.66. 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.
What 0.86 ft/yr means over time
Run 0.9 miles north of Strathmere, NJ's 0.86 ft/yr rate forward 25 years and it implies about 22 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
67 transects feed this segment's number; 72% of them individually measured retreat. Uncertainty on this specific number: 0.78 ft/yr either side. Sorted from fastest erosion to fastest growth across all 1211 measured segments nationally, this one lands at 215. Source: USGS Open-File Report 2010-1119. Rank 165 nationally for erosion belongs to Bolivar Peninsula, TX, 1302 miles from this stretch, measured at 1.41 ft/yr, 1.6x this stretch's rate. 1.9 miles away, Strathmere, NJ is the nearest other measured stretch: moderate erosion at 1.31 ft/yr.
Not this whole stretch, just Strathmere itself: the Coastal Change Hazards Portal is USGS's own live version of this data.