M4.0 earthquake 100 km S of Adak, Alaska
A magnitude 4.0 earthquake struck 100 km S of Adak, Alaska on Tue, Jun 30, 1987, 8:10 AM HADT (17:10 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M4.5 88 km S 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
- 4.0 (mb), light
- Local time
- UTC
- 1987-06-30 17:10:19 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 50.980° N, 176.474° 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 6 in the 30 days before it.
After
- 4.588 km S of Adak, Alaska · 14329 days ago · 33 km deep · 12 km away
- 4.784 km S of Adak, Alaska · 14328 days ago · 33 km deep · 16 km away
- 5.097 km S of Adak, Alaska · 14328 days ago · 33 km deep · 4 km away
- 4.583 km S of Adak, Alaska · 14328 days ago · 33 km deep · 17 km away
- 4.1110 km SSE of Adak, Alaska · 14307 days ago · 33 km deep · 35 km away
Before
- 4.588 km S of Adak, Alaska · 14335 days ago · 33 km deep · 12 km away
- 4.986 km S of Adak, Alaska · 14335 days ago · 33 km deep · 15 km away
- 4.386 km SSE of Adak, Alaska · 14343 days ago · 33 km deep · 35 km away
- 5.036 km SE of Adak, Alaska · 14358 days ago · 58 km deep · 77 km away
- 4.982 km SW of Adak, Alaska · 14358 days ago · 33 km deep · 79 km away
- 5.570 km WSW of Adak, Alaska · 14358 days ago · 33 km deep · 95 km away
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp000367b. Read Tue, Sep 22, 2026, 6:06 AM UTC.