Reviewed by USGSAlaska61y ago
M5.6 earthquake 13 km S of Chiniak, Alaska
Wednesday, September 8, 1965, 03:26:22 UTC · 57.493°N, 152.267°W
A magnitude 5.6 earthquake struck 13 km S of Chiniak, Alaska on Wednesday, September 8, 1965, 03:26:22 UTC, at a depth of 25.0 km (shallow). It is the strongest earthquake within 300 km since an M6.8 on September 4, 1965.
- Magnitude
- 5.6
- Moderate · mw
- Depth
- 25 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- V
- Moderate (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
3 kilotons of TNT
That is about 1/4 of the Hiroshima bomb. It released about 7 times the energy of a magnitude 5.0.
Tectonic setting
145 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 75 km
USGS has not published any M2.5+ earthquake within 75 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 166 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.9Kodiak Island region, AlaskaOctober 9, 1900 · 77 km E of this epicenter
- 7.14 km ENE of Karluk, AlaskaNovember 7, 1912 · 127 km W of this epicenter
- 7.0153 km SE of Halibut Cove, AlaskaDecember 23, 1906 · 203 km NE of this epicenter
- 6.9171 km SW of Akhiok, AlaskaFebruary 6, 1964 · 295 km SW of this epicenter
- 6.817 km N of Ouzinkie, AlaskaSeptember 4, 1965 · 67 km N of this epicenter
- 6.8Event 48 Novarupta-Mount Katmai area, Alaska PeninsulaJune 10, 1912 · 193 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1900M8.3
Kodiak Island
9 Oct 1900 · 86 km away · intensity VIII
Limited damage (under $1M)
- 1788M8.0
Unga Island
21 Jul 1788 · 70 km away · intensity VII
Limited damage (under $1M)tsunami
- 1792
Kodiak Island
1792 · 57 km away · intensity VII
Limited damage (under $1M)tsunami
- 1906M7.6
Aleutian Islands
23 Dec 1906 · 122 km away
- 1912M7.5
Alaska Peninsula
7 Nov 1912 · 163 km away · intensity V
- 1854
Gulf Of Alaska
27 Jan 1854 · 57 km away · intensity V
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.