The October 22, 1926 earthquake
M6.3near Davenport, California
A magnitude 6.3 earthquake 9.3 miles deep, 11.6 miles off Santa Cruz County. The 41st strongest in California’s record since 1900, and the strongest within 50 miles since a magnitude 6.5 on July 1, 1911. 2 aftershocks of magnitude 2.5 or more followed within 30 days.
The earthquake
- Magnitude
- 6.3
- moment magnitude (mw)
- Depth
- 9.3 mi
- 15.0 km below the surface
- Local time
- Friday, October 22, 1926
- 04:35 PST; 12:35 UTC
- In California’s record
- 41st
- strongest of 97,065 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event iscgem910174 (“22 km S of Davenport, California”). 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.
2
Aftershocks in 30 days
6.3
Largest aftershock, Oct 22, 1926 · its page
1
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.
- 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
- Santa Cruz CountyCA · 11.6 mi
- Monterey CountyCA · 19.0 mi
- San Mateo CountyCA · 21.2 mi
- Santa Clara CountyCA · 26.7 mi
- San Benito CountyCA · 31.6 mi
- Alameda CountyCA · 46.3 mi
Cities, largest first
- San JoseCA · 40.0 mi
- FremontCA · 49.6 mi
- SalinasCA · 32.7 mi
- SunnyvaleCA · 41.1 mi
- Santa ClaraCA · 40.6 mi
- Mountain ViewCA · 41.5 mi
- Redwood CityCA · 48.9 mi
- MilpitasCA · 46.5 mi
- Palo AltoCA · 40.8 mi
- Santa CruzCA · 14.8 mi
- GilroyCA · 36.9 mi
- CupertinoCA · 36.4 mi
Earthquakes around the epicentre
1,664 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 1, 1911M6.5
- August 2, 1903M6.2
- June 11, 1903M6.1
- March 10, 1910M5.8
- December 31, 1910M5.7
- November 8, 1914M5.5
- October 5, 1920M5.2
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.