The December 29, 1948 earthquake
M6.0near Verdi, California
A magnitude 6.0 earthquake, centred in Sierra County. The 66th strongest in California’s record since 1900, and the strongest within 50 miles since a magnitude 6.1 on June 25, 1933. 1 aftershock of magnitude 2.5 or more followed within 30 days.
The earthquake
- Magnitude
- 6.0
- local magnitude (ml)
- Depth
- —
- Not recorded
- Local time
- Wednesday, December 29, 1948
- 05:53 PDT; 12:53 UTC
- In California’s record
- 66th
- strongest of 97,065 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event ushis1643 (“6 km WNW of Verdi, 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.
1
Aftershocks in 30 days
4.8
Largest aftershock, Jan 20, 1949
0
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
- Sierra CountyCA · inside
- Nevada CountyCA · 8.3 mi
- Lassen CountyCA · 11.5 mi
- Plumas CountyCA · 11.5 mi
- Placer CountyCA · 16.6 mi
- Storey CountyNV · 20.6 mi
- Washoe CountyNV · 20.6 mi
- Carson CityNV · 26.9 mi
- Lyon CountyNV · 28.5 mi
- Douglas CountyNV · 30.5 mi
- El Dorado CountyCA · 33.5 mi
- Alpine CountyCA · 43.6 mi
- Churchill CountyNV · 47.7 mi
- Yuba CountyCA · 49.9 mi
Cities, largest first
- RenoNV · 12.3 mi
- SparksNV · 19.5 mi
- Carson CityNV · 32.7 mi
- FernleyNV · 47.5 mi
- South Lake TahoeCA · 43.3 mi
- TruckeeCA · 15.1 mi
Earthquakes around the epicentre
384 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 24, 1914M6.4
- June 25, 1933M6.1
- February 18, 1914M6.0
- June 22, 1909M5.9
- December 3, 1942M5.5
- March 30, 1943M5.3
- December 17, 1942M5.1
- March 3, 1909M5.0
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.