Rancho Palos Verdes, CA Coastal Erosion Rate
Is the coast eroding 1.2 miles southeast of Rancho Palos Verdes, CA?
Good news, and an honest one: USGS's data can't distinguish this stretch, 1.2 miles southeast of Rancho Palos Verdes, CA, from a flat trend. Whatever small movement it measured here is statistical noise, not a reliable direction, so none is claimed.
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 Rancho Palos Verdes, CA, rather than showing one arbitrary line. Segment center: 33.73, -118.35. 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.
How solid is this number
This reading comes from 50 individual transects averaged together, 34% of which measured erosion rather than growth. Uncertainty on this specific number: 0.18 ft/yr either side. The unadjusted figure here, 0.17 ft/yr, would place it 908 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. For scale: Oxnard, CA, 61 miles away, ranks 1086 of 1211 nationally for growth, 0.86 ft/yr. 1.2 miles away, Rancho Palos Verdes, CA is the nearest other measured stretch: slight erosion at 0.15 ft/yr.
One address near Rancho Palos Verdes: the Coastal Change Hazards Portal zooms past this stretch to the underlying map.