M2.5 earthquake 188 km S of Adak, Alaska
A magnitude 2.5 earthquake struck 188 km S of Adak, Alaska on Mon, Oct 31, 2016, 2:26 PM HADT (23:26 UTC), 10 km (6 mi) below the surface.
A larger quake followed: M4.7 166 km S 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
- 2.5 (ML, local (Richter)), micro
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2016-10-31 23:26:24 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 50.208° N, 177.125° W
- Region
- Alaska
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Magnitude estimates
Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 2.5 | ML, local (Richter) | USGS National Earthquake Information Center | Preferred · Reviewed |
| 2.5 | ML, local (Richter) | Alaska Earthquake Center | Preliminary |
Did you feel it?
No one has reported feeling this quake to the USGS.
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 9.4 km horizontally, 2.0 km in depth
- Depth from
- Operator assigned
- Station coverage gap
- 301°, poorly surrounded by stations
- Stations used
- 8
Nearby
Within 100 km, magnitude 1.5 and up: 4 in the 60 days after this one and 2 in the 30 days before it.
After
- 2.6131 km SSW of Adak, Alaska · 3611 days ago · 25 km deep · 72 km away
- 2.3133 km SSW of Adak, Alaska · 3611 days ago · 26 km deep · 69 km away
- 4.7166 km S of Adak, Alaska · 3597 days ago · 31 km deep · 69 km away
- 2.2176 km S of Adak, Alaska · 3589 days ago · 5 km deep · 54 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us10007652 (also filed as ak016e0srga0, ak14308743). Read Sun, Oct 4, 2026, 10:35 PM UTC.