The January 17, 1994 earthquake
M6.7Northridge, California
A magnitude 6.7 earthquake 11.3 miles deep, centred in Los Angeles County. The 16th strongest in California’s record since 1900, and the strongest within 50 miles in the catalogue, which runs from 1900. 919 aftershocks of magnitude 2.5 or more followed within 30 days.
Watch the sequence unfoldMagnitude 6.7 · January 17, 1994
How the ground moved
Every recorded earthquake in the sequence, in order, from the foreshocks to a month after.
The earthquake
- Magnitude
- 6.7
- moment magnitude (mw)
- Depth
- 11.3 mi
- 18.2 km below the surface
- Local time
- Monday, January 17, 1994
- 04:30 PST; 12:30 UTC
- In California’s record
- 16th
- strongest of 97,065 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event ci3144585 (“Northridge, 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.
919
Aftershocks in 30 days
5.9
Largest aftershock, Jan 17, 1994 · its page
400
On the first day
3
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
- Los Angeles CountyCA · inside
- Ventura CountyCA · 5.8 mi
- Orange CountyCA · 37.0 mi
- Kern CountyCA · 44.3 mi
- San Bernardino CountyCA · 45.1 mi
Cities, largest first
- Los AngelesCA · 15.2 mi
- Long BeachCA · 36.6 mi
- Santa AnaCA · 49.9 mi
- Santa ClaritaCA · 14.2 mi
- OxnardCA · 38.3 mi
- Huntington BeachCA · 46.9 mi
- GlendaleCA · 16.8 mi
- Garden GroveCA · 44.6 mi
- LancasterCA · 39.1 mi
- PalmdaleCA · 35.9 mi
- PomonaCA · 45.6 mi
- FullertonCA · 41.6 mi
Earthquakes around the epicentre
1,141 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
- February 9, 1971M6.6
- October 1, 1987M5.9
- February 9, 1971M5.8
- June 28, 1991M5.8
- February 9, 1971M5.8
- February 28, 1990M5.5
- October 22, 1916M5.5
- February 9, 1971M5.3
- August 4, 1927M5.3
- February 21, 1973M5.3
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.