M4.9 earthquake 124 km WSW of Adak, Alaska
A magnitude 4.9 earthquake struck 124 km WSW of Adak, Alaska on Fri, Jul 21, 1978, 10:50 AM GMT-10 (20:50 UTC), 54 km (34 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.9 (mb), light
- Local time
- UTC
- 1978-07-21 20:50:30 UTC
- Depth
- 54.0 km (33.6 mi), shallow
- Epicenter
- 51.433° N, 178.286° 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.
- Stations used
- 76
Nearby
Within 100 km, magnitude 1.9 and up: 0 in the 60 days after this one and 5 in the 30 days before it.
Before
- 3.9159 km WSW of Adak, Alaska · 17603 days ago · 68 km deep · 39 km away
- 4.4156 km WSW of Adak, Alaska · 17611 days ago · 56 km deep · 43 km away
- 4.9176 km WSW of Adak, Alaska · 17615 days ago · 67 km deep · 52 km away
- 4.6173 km WSW of Adak, Alaska · 17629 days ago · 66 km deep · 49 km away
- 5.9194 km W of Adak, Alaska · 17631 days ago · 33 km deep · 80 km away
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0000vpb. Read Tue, Sep 29, 2026, 9:48 AM UTC.