The December 21, 1973 earthquake
M5.2near Ferndale, California
A magnitude 5.2 earthquake 18.6 miles deep, 14.0 miles off Humboldt County. The 328th strongest in California’s record since 1900, and the strongest within 50 miles since a magnitude 5.4 on November 20, 1971.
The earthquake
- Magnitude
- 5.2
- body-wave magnitude (mb)
- Depth
- 18.6 mi
- 30.0 km below the surface
- Local time
- Friday, December 21, 1973
- 11:12 PST; 19:12 UTC
- In California’s record
- 328th
- strongest of 97,065 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event usp00004m1 (“28 km W of Ferndale, California”). The USGS event page carries the ShakeMap, felt reports and the official summary.
Counties and cities within 50 miles
Distance from the epicentre to each county boundary (zero when inside) and to each city centre.
Counties
- Humboldt CountyCA · 14.0 mi
Earthquakes around the epicentre
2,529 earthquakes of magnitude 3 or more within 50 miles of this epicentre since 1973.
Earlier earthquakes of magnitude 5 or more within 50 miles, strongest first
- January 22, 1923M7.1
- February 9, 1941M6.8
- July 14, 1918M6.5
- October 3, 1941M6.5
- June 6, 1932M6.5
- December 21, 1954M6.4
- April 23, 1906M6.4
- October 7, 1951M6.0
- September 22, 1952M6.0
- October 28, 1909M6.0
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.