Westhaven-Moonstone, CA Coastal Erosion Rate
What USGS measures 1.3 miles west of Westhaven-Moonstone, CA
Good news, and an honest one: USGS's data can't distinguish this stretch, 1.3 miles west of Westhaven-Moonstone, CA, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
What "Westhaven-Moonstone" 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 Westhaven-Moonstone, CA, rather than showing one arbitrary line. Segment center: 41.04, -124.12. 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 backs this reading up
This reading comes from 33 individual transects averaged together, 42% of which measured erosion rather than growth. Uncertainty on this specific number: 0.48 ft/yr either side. The unadjusted figure here, 0.03 ft/yr, would place it 801 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 National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. Rank 1200 nationally for growth belongs to Tokeland, WA, 395 miles from this stretch, measured at 5.19 ft/yr. 2.5 miles away, Westhaven-Moonstone, CA is the nearest other measured stretch: accretion (beach growing) at 1.85 ft/yr.
Not this whole stretch, just Westhaven-Moonstone itself: the Coastal Change Hazards Portal is USGS's own live version of this data.