M3.7 earthquake 73 km ESE of Adak, Alaska
A magnitude 3.7 earthquake struck 73 km ESE of Adak, Alaska on Sat, Oct 3, 1987, 5:39 PM HADT (02:39 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M5.3 88 km E 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
- 3.7 (mb), minor
- Local time
- UTC
- 1987-10-04 02:39:36 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 51.550° N, 175.713° 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: 3 in the 60 days after this one and 4 in the 30 days before it.
After
- 5.388 km E of Adak, Alaska · 14222 days ago · 64 km deep · 39 km away
- 3.333 km N of Adak, Alaska · 14216 days ago · 33 km deep · 90 km away
- 4.664 km SSE of Adak, Alaska · 14210 days ago · 33 km deep · 39 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00038yn. Read Tue, Sep 22, 2026, 5:49 AM UTC.