Carlsbad, CA Coastal Erosion Rate
Is the coast eroding 3 miles southwest of Carlsbad, CA?
3 miles southwest of Carlsbad, CA: USGS's transects didn't pick up a trend here that beats the survey's own uncertainty. That's the majority case nationally, and for this stretch specifically it means the coast is holding, not that the data failed to find anything.
What "Carlsbad" means on this page
This is a roughly 3.5-mile stretch of coast, not one address or parcel - USGS's own transects run every few hundred feet, but that's finer than any one property needs, so this page reports the stretch nearest Carlsbad, CA. Centered near 33.10°N, 117.32°W. 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
84 transects feed this segment's number; 70% of them individually measured retreat. Uncertainty on this specific number: 0.26 ft/yr either side. Taken at face value, this segment's raw -0.05 ft/yr reading would land it 716 of 1211 nationally - a number worth ignoring, since it's statistical noise rather than a real trend. Source: USGS National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. For scale: Gearhart, OR, 960 miles away, ranks 1167 of 1211 nationally for growth, 2.24 ft/yr. Carlsbad, CA, 1.8 miles off, is the adjacent measured stretch, itself no significant trend.
Not this whole stretch, just Carlsbad itself: the Coastal Change Hazards Portal is USGS's own live version of this data.