The October 28, 1958 earthquake

M6.6near Adak, Alaska

A magnitude 6.6 earthquake 18.6 miles deep, 3.8 miles off Aleutians West Census Area. The 173rd 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: 6.6; moment magnitude (mw)
Depth: 18.6 mi; 30.0 km below the surface
Local time: Tuesday, October 28, 1958; 20:44 NST; 07:44 UTC on Oct 29, 1958
Epicentre: 51.35°N, 179.36°E; 3.8 mi from Aleutians West Census Area
In Alaska’s record: 173rd; strongest of 124,625 since 1900
Within 50 miles: 1; county; more on this date

USGS ANSS Comprehensive Earthquake Catalog, event iscgem885339 (“283 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 · 3.8 mi

Earthquakes around the epicentre

2,841 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
February 6, 1916M7.0
October 12, 1926M6.7
June 1, 1955M6.7
June 20, 1955M6.7
April 26, 1930M6.7
October 13, 1926M6.7
March 27, 1940M6.6
May 20, 1930M6.5
February 2, 1930M6.5

USGS ANSS Comprehensive Earthquake Catalog. Local time is the time zone of the county nearest the epicentre. Magnitudes are as the catalogue reports them.