Vandenberg AFB, CA Coastal Erosion Rate
Is the coast eroding 6 miles west of Vandenberg AFB, CA?
Averaged across every transect USGS ran 6 miles west of Vandenberg AFB, CA, the shoreline has been moving inland at 0.33 feet a year, a real measured rate, not a regional estimate applied to this stretch. At that rate, the shoreline has lost roughly 3.3 feet over the last decade.
The grain of this number
Vandenberg AFB, CA is the nearest named place, 6 miles away, to a ~3.5-mile stretch of coast USGS has surveyed - the reading below covers that whole stretch, not a single property in it. Segment center: 34.73, -120.61. 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 0.33 ft/yr means over time
Run 6 miles west of Vandenberg AFB, CA's 0.33 ft/yr rate forward 25 years and it implies about 8 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
This reading comes from 9 individual transects averaged together, 100% of which measured erosion rather than growth. USGS's confidence interval here is ±0.15 ft/yr. This segment ranks 394 of 1211 measured US coastal segments, ordered from fastest erosion to fastest growth. Source: USGS National Shoreline Change data release (ScienceBase, DOI 10.5066/P94J0K7Z), Kratzmann 2024 / Data Report 1187. For scale: Boothville, LA, 1875 miles away, ranks 15 of 1211 nationally for erosion, 13.68 ft/yr, many times over this stretch's own rate. 2.5 miles away, Vandenberg AFB, CA is the nearest other measured stretch: also no significant trend.
Vandenberg AFB, CA on the source map: try the Coastal Change Hazards Portal, zoomable well past this page's ~3.5-mile grain.