Reviewed by USGSAlaska4y ago
M3.3 earthquake 78 km W of Akhiok, Alaska
Saturday, April 9, 2022, 06:00:45 UTC · 56.892°N, 155.459°W
A magnitude 3.3 earthquake struck 78 km W of Akhiok, Alaska on Saturday, April 9, 2022, 06:00:45 UTC, at a depth of 57.5 km (shallow).
- Magnitude
- 3.3
- Minor · ml
- Depth
- 58 km
- Shallow
- 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
1 tons of TNT
That is about 1/11,203 of the Hiroshima bomb. A magnitude 5.0 releases about 355 times more energy.
Tectonic setting
196 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
58 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 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 406 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.21938 Semidi Islands, Alaska EarthquakeNovember 10, 1938 · 255 km SW of this epicenter
- 8.22021 Chignik, Alaska EarthquakeJuly 29, 2021 · 227 km SW of this epicenter
- 7.9Kodiak Island region, AlaskaOctober 9, 1900 · 275 km E of this epicenter
- 7.82020 Perryville, Alaska EarthquakeJuly 22, 2020 · 281 km SW of this epicenter
- 7.14 km ENE of Karluk, AlaskaNovember 7, 1912 · 101 km NE of this epicenter
- 7.0113 km ESE of Chignik, AlaskaMay 4, 1923 · 142 km SW of this epicenter
- 7.026 km SSE of Karluk, AlaskaDecember 6, 1999 · 84 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 13 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1900M8.3
Kodiak Island
9 Oct 1900 · 122 km away · intensity VIII
Limited damage (under $1M)
- 1788M8.0
Unga Island
21 Jul 1788 · 150 km away · intensity VII
Limited damage (under $1M)tsunami
- 2020M7.8
Alaska
22 Jul 2020 · 281 km away · intensity VII
Limited damage (under $1M)tsunami
- 1970M6.0
Andreanof Islands
11 Mar 1970 · 116 km away · intensity V
Limited damage (under $1M)tsunami
- 1792
Kodiak Island
1792 · 210 km away · intensity VII
Limited damage (under $1M)tsunami
- 1938M8.2
Alaska
10 Nov 1938 · 239 km away · intensity VI
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.