Reviewed by USGSAlaska79y ago
M7.1 earthquake 90 km SE of King Cove, Alaska
Friday, May 14, 1948, 22:31:49 UTC · 54.593°N, 161.161°W
A magnitude 7.1 earthquake struck 90 km SE of King Cove, Alaska on Friday, May 14, 1948, 22:31:49 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M8.6 on April 1, 1946.
- Magnitude
- 7.1
- Major · mw
- Depth
- 25 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VI
- Strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
674 kilotons of TNT
That is about 45 times the Hiroshima bomb. It released about 1,413 times the energy of a magnitude 5.0.
Tectonic setting
108 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: shallow
25 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
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 200 km
USGS lists 1 M2.5+ earthquake within 200 km in the following 30 days; the largest was M6.1 on May 17, 1948. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 53 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 · 164 km SW of this epicenter
- 8.21938 Semidi Islands, Alaska EarthquakeNovember 10, 1938 · 201 km E of this epicenter
- 7.454 km SE of Sand Point, AlaskaMay 31, 1917 · 93 km NE of this epicenter
- 6.9105 km ESE of Perryville, AlaskaNovember 17, 1938 · 237 km NE of this epicenter
- 6.873 km SW of Sand Point, AlaskaJuly 2, 1922 · 26 km N of this epicenter
- 6.768 km SSE of King Cove, AlaskaApril 29, 1937 · 41 km W of this epicenter
- 6.6291 km S of Sand Point, AlaskaMay 13, 1910 · 224 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 6 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 · 164 km away · intensity VI
168 deaths$26 million damagetsunami
- 1938M8.2
Alaska
10 Nov 1938 · 203 km away · intensity VI
tsunami
- 1788M8.0
Alaska Peninsula
6 Aug 1788 · 46 km away
tsunami
- 1948M7.5
Alaska Peninsula
14 May 1948 · 15 km away
- 1820
East Aleutian Islands
1 Mar 1820 · 225 km away
tsunami
- 1868
Alaska Peninsula
15 May 1868 · 46 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.