Reviewed by USGSAlaska37y ago
M3.6 earthquake 41 km SW of Akhiok, Alaska
Thursday, September 7, 1989, 08:35:10 UTC · 56.643°N, 154.561°W
A magnitude 3.6 earthquake struck 41 km SW of Akhiok, Alaska on Thursday, September 7, 1989, 08:35:10 UTC, at a depth of 62.3 km (shallow).
- Magnitude
- 3.6
- Minor · ml
- Depth
- 62 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
4 tons of TNT
That is about 1/3,975 of the Hiroshima bomb. A magnitude 5.0 releases about 126 times more energy.
Tectonic setting
142 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
62 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 277 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 · 278 km SW of this epicenter
- 7.9Kodiak Island region, AlaskaOctober 9, 1900 · 231 km NE of this epicenter
- 7.14 km ENE of Karluk, AlaskaNovember 7, 1912 · 106 km N of this epicenter
- 7.0113 km ESE of Chignik, AlaskaMay 4, 1923 · 163 km SW of this epicenter
- 7.0164 km SE of Chignik, AlaskaSeptember 4, 1989 · 187 km SW of this epicenter
- 6.9105 km ESE of Perryville, AlaskaNovember 17, 1938 · 240 km SW of this epicenter
- 6.9143 km ESE of Chignik, AlaskaFebruary 13, 1951 · 142 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1900M8.3
Kodiak Island
9 Oct 1900 · 82 km away · intensity VIII
Limited damage (under $1M)
- 1788M8.0
Unga Island
21 Jul 1788 · 103 km away · intensity VII
Limited damage (under $1M)tsunami
- 1970M6.0
Andreanof Islands
11 Mar 1970 · 103 km away · intensity V
Limited damage (under $1M)tsunami
- 1792
Kodiak Island
1792 · 161 km away · intensity VII
Limited damage (under $1M)tsunami
- 1938M8.2
Alaska
10 Nov 1938 · 269 km away · intensity VI
tsunami
- 1906M7.6
Aleutian Islands
23 Dec 1906 · 46 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.