M4.5 earthquake 67 km SSE of Atka, Alaska
A magnitude 4.5 earthquake struck 67 km SSE of Atka, Alaska on Thu, Sep 20, 1973, 8:58 AM GMT-10 (18:58 UTC), 39 km (24 mi) below the surface.
A larger quake followed: M5.0 70 km SSE of Atka, Alaska. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.5 (mb), light
- Local time
- UTC
- 1973-09-20 18:58:01 UTC
- Depth
- 39.0 km (24.2 mi), shallow
- Epicenter
- 51.630° N, 173.867° W
- Region
- Alaska
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Did you feel it?
No one has reported feeling this quake to the USGS.
How well it is located
Reviewed by a seismologist.
- Stations used
- 38
Nearby
Within 100 km, magnitude 1.5 and up: 5 in the 60 days after this one and 6 in the 30 days before it.
After
- 5.070 km SSE of Atka, Alaska · 19358 days ago · 36 km deep · 12 km away
- 4.1134 km SSE of Atka, Alaska · 19358 days ago · 33 km deep · 69 km away
- 5.4Andreanof Islands, Aleutian Islands, Alaska · 19358 days ago · 49 km deep · 12 km away
- 6.399 km SW of Atka, Alaska · 19313 days ago · 41 km deep · 95 km away
- 4.092 km SW of Atka, Alaska · 19311 days ago · 49 km deep · 91 km away
Before
- 4.976 km SE of Atka, Alaska · 19376 days ago · 42 km deep · 32 km away
- 4.646 km SE of Atka, Alaska · 19378 days ago · 42 km deep · 33 km away
- 4.562 km SSE of Atka, Alaska · 19384 days ago · 58 km deep · 11 km away
- 5.162 km SE of Atka, Alaska · 19385 days ago · 51 km deep · 18 km away
- 4.865 km SSE of Atka, Alaska · 19385 days ago · 45 km deep · 14 km away
- 4.769 km SE of Atka, Alaska · 19388 days ago · 38 km deep · 29 km away
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00003g3. Read Tue, Sep 22, 2026, 10:25 PM UTC.