M4.6 earthquake 19 km S of Adak, Alaska
A magnitude 4.6 earthquake struck 19 km S of Adak, Alaska on Sun, May 20, 1973, 4:20 AM GMT-10 (14:20 UTC), 56 km (35 mi) below the surface.
A larger quake followed: M5.5 18 km W of Adak, Alaska. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.6 (mb), light
- Local time
- UTC
- 1973-05-20 14:20:33 UTC
- Depth
- 56.0 km (34.8 mi), shallow
- Epicenter
- 51.701° N, 176.684° 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
- 21
Nearby
Within 100 km, magnitude 1.6 and up: 3 in the 60 days after this one and 1 in the 30 days before it.
After
- 4.685 km ESE of Adak, Alaska · 19477 days ago · 59 km deep · 87 km away
- 5.518 km W of Adak, Alaska · 19449 days ago · 62 km deep · 24 km away
- 5.138 km ENE of Adak, Alaska · 19430 days ago · 63 km deep · 50 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00001vm. Read Tue, Sep 22, 2026, 4:53 AM UTC.