M4.0 earthquake 46 km WSW of Atka, Alaska
A magnitude 4.0 earthquake struck 46 km WSW of Atka, Alaska on Sun, Apr 20, 1997, 2:02 PM HADT (23:02 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M4.7 41 km SSW 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
- 4.0 (mb, body-wave), light
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1997-04-20 23:02:20 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 51.971° N, 174.764° 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.
- Depth from
- OPERATOR_ASSIGNED
Nearby
Within 100 km, magnitude 1.5 and up: 5 in the 60 days after this one and 4 in the 30 days before it.
After
- 4.741 km SSW of Atka, Alaska · 10749 days ago · 49 km deep · 30 km away
- 3.467 km W of Atka, Alaska · 10736 days ago · 33 km deep · 33 km away
- 4.712 km ESE of Atka, Alaska · 10731 days ago · 98 km deep · 53 km away
- 3.939 km ENE of Adak, Alaska · 10718 days ago · 33 km deep · 92 km away
- 3.575 km ESE of Adak, Alaska · 10705 days ago · 33 km deep · 81 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00080vs. Read Thu, Oct 1, 2026, 7:48 PM UTC.