The May 2, 1983 earthquake
M6.7Coalinga, California
A magnitude 6.7 earthquake 6.0 miles deep, centred in Fresno County. The 16th strongest in California’s record since 1900, and the strongest within 50 miles in the catalogue, which runs from 1900. 740 aftershocks of magnitude 2.5 or more followed within 30 days.
Watch the sequence unfoldMagnitude 6.7 · May 2, 1983
How the ground moved
Every recorded earthquake in the sequence, in order, through the month after.
The earthquake
- Magnitude
- 6.7
- local magnitude (ml)
- Depth
- 6.0 mi
- 9.6 km below the surface
- Local time
- Monday, May 2, 1983
- 16:42 PDT; 23:42 UTC
- In California’s record
- 16th
- strongest of 97,065 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event nc1091100 (“The 1983 Coalinga, California Earthquake”). 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.
740
Aftershocks in 30 days
5.5
Largest aftershock, May 2, 1983 · its page
319
On the first day
0
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.
Counties and cities within 50 miles
Distance from the epicentre to each county boundary (zero when inside) and to each city centre.
Counties
- Fresno CountyCA · inside
- San Benito CountyCA · 17.2 mi
- Monterey CountyCA · 17.7 mi
- Kings CountyCA · 20.0 mi
- San Luis Obispo CountyCA · 31.3 mi
- Kern CountyCA · 31.3 mi
- Madera CountyCA · 36.7 mi
- Tulare CountyCA · 43.7 mi
- Merced CountyCA · 48.7 mi
Earthquakes around the epicentre
1,668 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
- March 10, 1922M6.5
- March 2, 1901M6.4
- May 25, 1905M6.1
- June 7, 1934M5.8
- July 25, 1926M5.8
- June 27, 1966M5.5
- October 25, 1982M5.4
- February 27, 1972M5.2
- December 28, 1939M5.2
- June 7, 1934M5.1
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.