Reviewed by USGSAlaska35y ago
M3.1 earthquake 47 km SW of Nelson Lagoon, Alaska
Saturday, June 22, 1991, 16:23:11 UTC · 55.742°N, 161.809°W
A magnitude 3.1 earthquake struck 47 km SW of Nelson Lagoon, Alaska on Saturday, June 22, 1991, 16:23:11 UTC, at a depth of 127.5 km (intermediate).
- Magnitude
- 3.1
- Minor · md
- Depth
- 128 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
674 kg of TNT
That is about 1/22,353 of the Hiroshima bomb. A magnitude 5.0 releases about 708 times more energy.
Tectonic setting
241 km
from the nearest mapped plate boundary, between the North American and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: intermediate
128 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 50 km
USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 169 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.6The 1946 Unimak Island, Alaska EarthquakeApril 1, 1946 · 259 km S of this epicenter
- 8.21938 Semidi Islands, Alaska EarthquakeNovember 10, 1938 · 237 km E of this epicenter
- 7.454 km SE of Sand Point, AlaskaMay 31, 1917 · 147 km SE of this epicenter
- 7.190 km SE of King Cove, AlaskaMay 14, 1948 · 134 km S of this epicenter
- 7.071 km SE of King Cove, AlaskaMay 30, 1991 · 131 km S of this epicenter
- 6.9105 km ESE of Perryville, AlaskaNovember 17, 1938 · 259 km E of this epicenter
- 6.873 km SW of Sand Point, AlaskaJuly 2, 1922 · 108 km S of this epicenter
- 6.7121 km SE of Chignik, AlaskaFebruary 13, 1979 · 294 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 168 recorded deaths. The most severe:
- 1946M8.6
Unimak Island
1 Apr 1946 · 259 km away · intensity VI
168 deaths$26 million damagetsunami
- 1938M8.2
Alaska
10 Nov 1938 · 218 km away · intensity VI
tsunami
- 1788M8.0
Alaska Peninsula
6 Aug 1788 · 97 km away
tsunami
- 1948M7.5
Alaska Peninsula
14 May 1948 · 147 km away
- 1957M7.5
Aleutian Islands: Fox Islands
22 Mar 1957 · 230 km away · intensity V
- 1820
East Aleutian Islands
1 Mar 1820 · 226 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.