Alaska earthquakes

M4.9 earthquake 50 km ESE of Adak, Alaska

A magnitude 4.9 earthquake struck 50 km ESE of Adak, Alaska on Sun, Sep 27, 1987, 4:16 PM HADT (01:16 UTC), 67 km (42 mi) below the surface.

A larger quake followed: M5.3 88 km E of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude
4.9 (mb), light
Local time
UTC
1987-09-28 01:16:25 UTC
Depth
67.0 km (41.6 mi), shallow
Epicenter
51.787° N, 175.917° 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.

Nearby

Within 100 km, magnitude 1.9 and up: 5 in the 60 days after this one and 4 in the 30 days before it.

After

  1. 4.963 km SSW of Adak, Alaska · 14241 days ago · 33 km deep · 86 km away
  2. 3.773 km ESE of Adak, Alaska · 14235 days ago · 33 km deep · 30 km away
  3. 5.388 km E of Adak, Alaska · 14224 days ago · 64 km deep · 39 km away
  4. 3.333 km N of Adak, Alaska · 14218 days ago · 33 km deep · 61 km away
  5. 4.664 km SSE of Adak, Alaska · 14212 days ago · 33 km deep · 51 km away

Before

  1. 5.065 km SE of Adak, Alaska · 14244 days ago · 33 km deep · 42 km away
  2. 5.143 km E of Adak, Alaska · 14259 days ago · 49 km deep · 17 km away
  3. 4.8110 km ESE of Adak, Alaska · 14268 days ago · 33 km deep · 66 km away
  4. 4.569 km SE of Adak, Alaska · 14269 days ago · 33 km deep · 42 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event usp00038su. Read Thu, Sep 24, 2026, 5:24 AM UTC.