The October 27, 1940 earthquake
M5.1Olympic Peninsula, Washington
A magnitude 5.1 earthquake, centred in Mason County. The 17th strongest in Washington’s record since 1900, and the strongest within 50 miles since a magnitude 6.1 on November 12, 1939.
The earthquake
- Magnitude
- 5.1
- local magnitude (ml)
- Depth
- —
- Not recorded
- Local time
- Sunday, October 27, 1940
- 14:29 PST; 22:29 UTC
- In Washington’s record
- 17th
- strongest of 5,002 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event ushis1339 (“Olympic Peninsula, Washington”). The USGS event page carries the ShakeMap, felt reports and the official summary.
Counties and cities within 50 miles
Distance from the epicentre to each county boundary (zero when inside) and to each city centre.
Counties
- Mason CountyWA · inside
- Grays Harbor CountyWA · 9.1 mi
- Thurston CountyWA · 12.2 mi
- Jefferson CountyWA · 22.5 mi
- Pierce CountyWA · 26.7 mi
- Pacific CountyWA · 28.2 mi
- Lewis CountyWA · 28.2 mi
- Kitsap CountyWA · 28.8 mi
- King CountyWA · 42.3 mi
Cities, largest first
- TacomaWA · 44.3 mi
- LakewoodWA · 41.0 mi
- LaceyWA · 30.3 mi
- OlympiaWA · 26.2 mi
- BremertonWA · 39.7 mi
- University PlaceWA · 40.0 mi
- TumwaterWA · 27.0 mi
- Port OrchardWA · 42.9 mi
- CentraliaWA · 38.7 mi
- AberdeenWA · 24.8 mi
- Gig HarborWA · 38.7 mi
- YelmWA · 39.8 mi
Earthquakes around the epicentre
113 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
- November 12, 1939M6.1
- March 16, 1904M5.3
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.