M4.6 earthquake 36 km SW of Unalaska, Alaska
A magnitude 4.6 earthquake struck 36 km SW of Unalaska, Alaska on Mon, Aug 31, 1987, 8:22 PM AKDT (04:22 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M4.7 65 km WSW of Unalaska, 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
- 1987-09-01 04:22:12 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 53.656° N, 166.956° 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
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.6 and up: 4 in the 60 days after this one and 5 in the 30 days before it.
After
- 4.636 km WSW of Unalaska, Alaska · 14266 days ago · 33 km deep · 14 km away
- 4.535 km WSW of Unalaska, Alaska · 14266 days ago · 33 km deep · 5 km away
- 4.765 km WSW of Unalaska, Alaska · 14249 days ago · 33 km deep · 30 km away
- 4.7114 km SSW of Unalaska, Alaska · 14241 days ago · 33 km deep · 85 km away
Before
- 4.941 km WSW of Unalaska, Alaska · 14266 days ago · 33 km deep · 15 km away
- 4.637 km WSW of Unalaska, Alaska · 14266 days ago · 33 km deep · 12 km away
- 5.045 km WSW of Dutch Harbor, Alaska · 14266 days ago · 33 km deep · 21 km away
- 4.772 km SW of Unalaska, Alaska · 14271 days ago · 33 km deep · 35 km away
- 4.644 km W of Dutch Harbor, Alaska · 14290 days ago · 33 km deep · 25 km away
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00037zm. Read Tue, Sep 22, 2026, 7:32 AM UTC.