Longport, NJ Coastal Erosion Rate
What USGS measures 1.6 miles southwest of Longport, NJ
1.6 miles southwest of Longport, NJ, the coast is advancing, not retreating, at a measured 2.33 feet a year, sediment accumulating faster than any erosion USGS recorded here. At that rate, the shoreline has gained roughly 23.3 feet over the last decade.
What this reading actually covers
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 Longport, NJ, rather than showing one arbitrary line. Segment center: 39.30, -74.55. 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 2.33 ft/yr means over time
Holding the 2.33 ft/yr accretion rate 1.6 miles southwest of Longport, NJ for 25 years would add roughly 58 feet of shoreline, again assuming nothing about the local sediment supply changes.
What backs this reading up
Averaging 84 separate transects produced this segment's rate, with 35% individually reading as erosion, rather than relying on any single survey line. The published margin on this reading runs ±1.17 ft/yr. Sorted from fastest erosion to fastest growth across all 1211 measured segments nationally, this one lands at 1168. Source: USGS Open-File Report 2010-1119. For scale: Fields Landing, CA, 2595 miles away, ranks 1157 of 1211 nationally for growth, 2.04 ft/yr, 0.9x this stretch's rate. 2.2 miles up the coast, Ocean City, NJ shows 2.2 ft/yr of accreting.
Longport, NJ on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.