Reviewed by USGSAlaska5y ago
M2.8 earthquake 88 km SSE of Akutan, Alaska
Friday, September 10, 2021, 03:12:49 UTC · 53.409°N, 165.221°W
A magnitude 2.8 earthquake struck 88 km SSE of Akutan, Alaska on Friday, September 10, 2021, 03:12:49 UTC, at a depth of 35.0 km (shallow).
- Magnitude
- 2.8
- Minor · ml
- Depth
- 35 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
239 kg of TNT
That is about 1/63,000 of the Hiroshima bomb. A magnitude 5.0 releases about 1,995 times more energy.
Tectonic setting
74 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
35 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 557 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 · 158 km E of this epicenter
- 7.881 km E of Nikolski, AlaskaJuly 2, 1965 · 168 km W of this epicenter
- 7.190 km SE of King Cove, AlaskaMay 14, 1948 · 296 km NE of this epicenter
- 7.139 km S of Akutan, AlaskaMarch 22, 1957 · 55 km NW of this epicenter
- 7.135 km SW of Nikolski, AlaskaMarch 11, 1957 · 277 km W of this epicenter
- 7.071 km SE of King Cove, AlaskaMay 30, 1991 · 269 km NE of this epicenter
- 7.0203 km SSE of Unalaska, AlaskaAugust 22, 1940 · 140 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 9 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 · 158 km away · intensity VI
168 deaths$26 million damagetsunami
- 1965M6.5
Aleutian Islands: Fox Islands
2 Jul 1965 · 161 km away
Limited damage (under $1M)tsunami
- 1917M7.9
Alaska Peninsula
31 May 1917 · 297 km away · intensity V
- 1902M7.8
Aleutian Islands: Fox Islands
1 Jan 1902 · 190 km away
- 1957M7.5
Aleutian Islands: Fox Islands
22 Mar 1957 · 177 km away · intensity V
- 1962M6.5
Aleutian Islands: Fox Islands
21 Dec 1962 · 246 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.