Trinidad, CA Coastal Erosion Rate
What USGS measures right at Trinidad, CA
Good news, and an honest one: USGS's data can't distinguish this stretch, right at Trinidad, CA, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
What "Trinidad" 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 Trinidad, CA, rather than showing one arbitrary line. Segment center: 41.06, -124.14. The survey behind it runs to 1852-2016, in USGS's California 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.
How solid is this number
46 transects feed this segment's number; 67% of them individually measured retreat. USGS's confidence interval here is ±0.49 ft/yr. The unadjusted figure here, -0.13 ft/yr, would place it 607 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. Kennebunkport, ME sits at national rank 933 for growth (0.22 ft/yr), one reference point among the 1211 scored segments, 2704 miles from here. Westhaven-Moonstone, CA, 2.1 miles off, is the adjacent measured stretch, itself no significant trend.
Not this whole stretch, just Trinidad itself: the Coastal Change Hazards Portal is USGS's own live version of this data.