The February 21, 1957 earthquake
M6.8near Nikolski, Alaska
A magnitude 6.8 earthquake 64.7 miles deep, 24.9 miles off Aleutians West Census Area. The 87th strongest in Alaska’s record since 1900, and the strongest within 50 miles since a magnitude 7.4 on April 17, 1916.
The earthquake
- Magnitude
- 6.8
- moment magnitude (mw)
- Depth
- 64.7 mi
- 104.1 km below the surface
- Local time
- Thursday, February 21, 1957
- 03:30 NST; 14:30 UTC
- In Alaska’s record
- 87th
- strongest of 124,625 since 1900
USGS ANSS Comprehensive Earthquake Catalog, event iscgem885978 (“167 km W of Nikolski, 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 · 24.9 mi
Earthquakes around the epicentre
459 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 17, 1916M7.4
- December 5, 1930M6.5
- August 18, 1925M6.0
USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.