Fort Hunter Liggett, CA Coastal Erosion Rate
Is the coast eroding 14.2 miles southwest of Fort Hunter Liggett, CA?
USGS's shoreline-change data puts this stretch, 14.2 miles southwest of Fort Hunter Liggett, CA, at 0.46 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 4.6 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 Fort Hunter Liggett, CA, rather than showing one arbitrary line. Segment center: 35.91, -121.46. USGS's California assessment last surveyed this stretch through 1852-2016, computing the rate with its LRR method. Other US regions were surveyed in different years, sometimes decades apart, so this page states its own rather than implying one national vintage.
What 0.46 ft/yr means over time
Run 14.2 miles southwest of Fort Hunter Liggett, CA's 0.46 ft/yr rate forward 25 years and it implies about 12 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
31 transects feed this segment's number; 100% of them individually measured retreat. Uncertainty on this specific number: 0.25 ft/yr either side. Among the 1211 US coastal segments with a measurable trend, this one ranks 319 for erosion, 1 being the fastest-retreating coast in the dataset. Source: USGS National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. Siasconset, MA sits at national rank 173 for erosion (1.33 ft/yr), one reference point among the 1211 scored segments, 2762 miles from here. Fort Hunter Liggett, CA, 1.7 miles off, is the adjacent measured stretch, reading slight erosion at 0.4 ft/yr.
Fort Hunter Liggett, CA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.