Reviewed by USGSAlaska4y ago
M2.5 earthquake 258 km SE of Chignik, Alaska
Wednesday, May 18, 2022, 20:30:39 UTC · 54.441°N, 155.944°W
A magnitude 2.5 earthquake struck 258 km SE of Chignik, Alaska on Wednesday, May 18, 2022, 20:30:39 UTC, at a depth of 11.6 km (shallow).
- Magnitude
- 2.5
- Minor · ml
- Depth
- 12 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
85 kg of TNT
That is about 1/177,558 of the Hiroshima bomb. A magnitude 5.0 releases about 5,623 times more energy.
Tectonic setting
14 km
from the nearest mapped plate boundary, between the North American and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
12 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 269 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 · 165 km NW of this epicenter
- 8.22021 Chignik, Alaska EarthquakeJuly 29, 2021 · 161 km NW of this epicenter
- 7.82020 Perryville, Alaska EarthquakeJuly 22, 2020 · 184 km NW of this epicenter
- 7.62020 Sand Point, Alaska EarthquakeOctober 19, 2020 · 238 km W of this epicenter
- 7.454 km SE of Sand Point, AlaskaMay 31, 1917 · 260 km W of this epicenter
- 7.0113 km ESE of Chignik, AlaskaMay 4, 1923 · 164 km N of this epicenter
- 7.0164 km SE of Chignik, AlaskaSeptember 4, 1989 · 103 km N of this epicenter
- 6.9112 km E of Chignik, AlaskaOctober 11, 2021 · 210 km N 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. The most severe:
- 2020M7.8
Alaska
22 Jul 2020 · 184 km away · intensity VII
Limited damage (under $1M)tsunami
- 1938M8.2
Alaska
10 Nov 1938 · 193 km away · intensity VI
tsunami
- 2021M8.2
Alaska Peninsula
29 Jul 2021 · 156 km away · intensity VIII
tsunami
- 1906M7.6
Aleutian Islands
23 Dec 1906 · 297 km away
- 2020M7.6
Alaska
19 Oct 2020 · 238 km away · intensity IX
tsunami
- 1989M6.9
Alaska
4 Sep 1989 · 135 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.