The July 29, 2008 earthquake
M5.4near Chino Hills, CA
A magnitude 5.4 earthquake 9.6 miles deep, centred in San Bernardino County. The 218th strongest in California’s record since 1900, and the strongest within 50 miles since a magnitude 5.6 on October 16, 1999. 8 aftershocks of magnitude 2.5 or more followed within 30 days.
The earthquake
- Magnitude
- 5.4
- moment magnitude (mw)
- Depth
- 9.6 mi
- 15.5 km below the surface
- Local time
- Tuesday, July 29, 2008
- 11:42 PDT; 18:42 UTC
- In California’s record
- 218th
- strongest of 97,065 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event ci14383980 (“5km S of Chino Hills, 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.
8
Aftershocks in 30 days
3.8
Largest aftershock, Jul 29, 2008
4
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
- San Bernardino CountyCA · inside
- Orange CountyCA · 1.0 mi
- Los Angeles CountyCA · 1.0 mi
- Riverside CountyCA · 6.6 mi
- San Diego CountyCA · 34.0 mi
Cities, largest first
- Los AngelesCA · 37.2 mi
- Long BeachCA · 25.8 mi
- AnaheimCA · 6.4 mi
- RiversideCA · 21.4 mi
- IrvineCA · 18.7 mi
- Santa AnaCA · 16.1 mi
- San BernardinoCA · 30.1 mi
- FontanaCA · 20.6 mi
- Moreno ValleyCA · 32.2 mi
- Huntington BeachCA · 22.0 mi
- GlendaleCA · 31.8 mi
- OntarioCA · 11.0 mi
Earthquakes around the epicentre
1,105 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
- April 21, 1918M6.7
- January 17, 1994M6.7
- February 9, 1971M6.6
- March 10, 1933M6.4
- July 22, 1923M6.2
- May 15, 1910M6.0
- October 1, 1987M5.9
- January 17, 1994M5.9
- June 28, 1991M5.8
- February 9, 1971M5.8
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.