The August 26, 2012 earthquake
M5.3near Brawley, CA
A magnitude 5.3 earthquake 5.2 miles deep, centred in Imperial County. The 265th strongest in California’s record since 1900, and the strongest within 50 miles since a magnitude 5.7 on June 14, 2010. 89 aftershocks of magnitude 2.5 or more followed within 30 days.
Watch the sequence unfoldMagnitude 5.3 · August 26, 2012
How the ground moved
Every recorded earthquake in the sequence, in order, from the foreshocks to a month after.
The earthquake
- Magnitude
- 5.3
- moment magnitude (mw)
- Depth
- 5.2 mi
- 8.3 km below the surface
- Local time
- Sunday, August 26, 2012
- 12:31 PDT; 19:31 UTC
- In California’s record
- 265th
- strongest of 97,065 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event ci15199681 (“5km NNW of Brawley, 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.
89
Aftershocks in 30 days
5.4
Largest aftershock, Aug 26, 2012 · its page
76
On the first day
19
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
- Imperial CountyCA · inside
- San Diego CountyCA · 30.8 mi
- La Paz CountyAZ · 49.2 mi
Earthquakes around the epicentre
3,071 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
- May 18, 1940M6.9
- October 21, 1942M6.6
- April 8, 1968M6.6
- November 24, 1987M6.6
- October 15, 1979M6.4
- March 19, 1954M6.4
- April 18, 1906M6.3
- November 23, 1987M6.2
- June 22, 1915M6.0
- March 25, 1937M6.0
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.