M4.1 earthquake 110 km SSE of Adak, Alaska
A magnitude 4.1 earthquake struck 110 km SSE of Adak, Alaska on Tue, Jul 21, 1987, 9:58 PM HADT (06:58 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M4.8 110 km ESE 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
- 4.1 (mb, body-wave), light
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1987-07-22 06:58:46 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 50.976° N, 175.971° 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: 2 in the 60 days after this one and 8 in the 30 days before it.
After
- 4.569 km SE of Adak, Alaska · 14279 days ago · 33 km deep · 48 km away
- 4.8110 km ESE of Adak, Alaska · 14278 days ago · 33 km deep · 64 km away
Before
- 4.3159 km SSW of Atka, Alaska · 14335 days ago · 33 km deep · 80 km away
- 4.583 km S of Adak, Alaska · 14340 days ago · 33 km deep · 43 km away
- 5.097 km S of Adak, Alaska · 14340 days ago · 33 km deep · 33 km away
- 4.784 km S of Adak, Alaska · 14340 days ago · 33 km deep · 38 km away
- 4.588 km S of Adak, Alaska · 14340 days ago · 33 km deep · 35 km away
- 4.0100 km S of Adak, Alaska · 14340 days ago · 33 km deep · 35 km away
- 4.588 km S of Adak, Alaska · 14347 days ago · 33 km deep · 42 km away
- 4.986 km S of Adak, Alaska · 14347 days ago · 33 km deep · 44 km away
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00036uw. Read Sat, Oct 3, 2026, 7:45 PM UTC.