The December 8, 1956 earthquake
M6.5near Adak, Alaska
A magnitude 6.5 earthquake 15.5 miles deep, 2.0 miles off Aleutians West Census Area. The 187th strongest in Alaska’s record since 1900, and the strongest within 50 miles since a magnitude 6.7 on June 20, 1955.
The earthquake
- Magnitude
- 6.5
- moment magnitude (mw)
- Depth
- 15.5 mi
- 25.0 km below the surface
- Local time
- Saturday, December 8, 1956
- 05:10 NST; 16:10 UTC
- In Alaska’s record
- 187th
- strongest of 124,625 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event iscgem888989 (“184 km WSW of Adak, Alaska”). 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
- Aleutians West Census AreaAK · 2.0 mi
Earthquakes around the epicentre
3,858 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
- March 21, 1905M7.2
- July 5, 1929M7.0
- March 30, 1913M6.9
- October 12, 1926M6.7
- June 1, 1955M6.7
- June 20, 1955M6.7
- October 13, 1926M6.7
- April 17, 1954M6.6
- December 11, 1944M6.6
- January 26, 1943M6.5
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.