Alaska earthquakes

M5.4 earthquake 193 km WSW of Adak, Alaska

A magnitude 5.4 earthquake struck 193 km WSW of Adak, Alaska on Tue, Feb 17, 1987, 7:28 PM HAST (05:28 UTC), 33 km (21 mi) below the surface.

A larger quake followed: M5.7 274 km WSW of Adak, Alaska. This one was a foreshock.

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The earthquake

Magnitude
5.4 (mw), moderate
Local time
UTC
1987-02-18 05:28:23 UTC
Depth
33.0 km (20.5 mi), shallow
Epicenter
51.344° N, 179.298° 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 2.4 and up: 8 in the 60 days after this one and 2 in the 30 days before it.

After

  1. 5.7274 km WSW of Adak, Alaska · 14445 days ago · 54 km deep · 81 km away
  2. 4.4279 km WSW of Adak, Alaska · 14445 days ago · 33 km deep · 88 km away
  3. 4.8280 km WSW of Adak, Alaska · 14445 days ago · 33 km deep · 88 km away
  4. 5.1278 km WSW of Adak, Alaska · 14445 days ago · 33 km deep · 84 km away
  5. 4.8130 km WSW of Adak, Alaska · 14440 days ago · 33 km deep · 65 km away
  6. 5.1130 km WSW of Adak, Alaska · 14424 days ago · 33 km deep · 72 km away
  7. 4.7242 km WSW of Adak, Alaska · 14412 days ago · 33 km deep · 52 km away
  8. 4.3190 km WSW of Adak, Alaska · 14406 days ago · 33 km deep · 42 km away

Before

  1. 6.2194 km WSW of Adak, Alaska · 14461 days ago · 33 km deep · 5 km away
  2. 4.3Andreanof Islands, Aleutian Islands, Alaska · 14471 days ago · 102 km deep · 51 km away

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event usp00032ka (also filed as gcmtb021887b, ushis4014, gcmt19870218052823, iscgem474834). Read Tue, Sep 22, 2026, 11:14 AM UTC.