The May 23, 1954 earthquake
M5.0near Grapevine, CA
A magnitude 5.0 earthquake 9.0 miles deep, centred in Kern County. The 439th strongest in California’s record since 1900, and the strongest within 50 miles since a magnitude 5.4 on January 12, 1954. 5 aftershocks of magnitude 2.5 or more followed within 30 days.
The earthquake
- Magnitude
- 5.0
- local magnitude (ml)
- Depth
- 9.0 mi
- 14.5 km below the surface
- Local time
- Sunday, May 23, 1954
- 16:52 PDT; 23:52 UTC
- In California’s record
- 439th
- strongest of 97,065 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event ci3299932 (“7km WNW of Grapevine, CA”). The USGS event page carries the ShakeMap, felt reports and the official summary.
Aftershocks
Earthquakes of magnitude 2.5 or more within 20 miles of the epicentre in the 30 days after.
5
Aftershocks in 30 days
3.5
Largest aftershock, Jun 17, 1954
1
On the first day
1
In the 7 days before
- The search radius is the surface rupture length expected for an earthquake of this magnitude (Wells and Coppersmith, 1994), at least 20 and at most 600 miles, so a great earthquake's sequence is counted along its whole fault.
- Before the modern seismic networks of the 1970s many small aftershocks went unrecorded, so early sequences read short.
Counties and cities within 50 miles
Distance from the epicentre to each county boundary (zero when inside) and to each city centre.
Counties
- Kern CountyCA · inside
- Ventura CountyCA · 10.9 mi
- Los Angeles CountyCA · 12.0 mi
- Santa Barbara CountyCA · 25.4 mi
- San Luis Obispo CountyCA · 27.0 mi
Cities, largest first
- BakersfieldCA · 26.7 mi
- Santa ClaritaCA · 47.6 mi
- MoorparkCA · 47.7 mi
- Santa PaulaCA · 42.5 mi
- WascoCA · 47.9 mi
- ShafterCA · 37.1 mi
- ArvinCA · 18.4 mi
- FillmoreCA · 39.6 mi
- McFarlandCA · 50.0 mi
- CarpinteriaCA · 49.2 mi
- TehachapiCA · 33.7 mi
Earthquakes around the epicentre
642 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
- July 21, 1952M7.5
- October 22, 1916M6.0
- December 23, 1905M5.8
- July 21, 1952M5.8
- July 29, 1952M5.7
- July 31, 1952M5.6
- July 25, 1952M5.6
- July 23, 1952M5.5
- July 25, 1952M5.5
- August 22, 1952M5.5
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.