M4.0 earthquake 173 km SSE of Nikolski, Alaska
A magnitude 4.0 earthquake struck 173 km SSE of Nikolski, Alaska on Fri, Sep 29, 2017, 2:40 AM AKDT (10:40 UTC), 10 km (6 mi) below the surface.
A larger quake followed: M4.4 91 km SE of Nikolski, Alaska. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.0 (mb, body-wave), light
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2017-09-29 10:40:30 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 51.462° N, 168.044° 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 |
|---|---|---|---|
| 4.0 | mb, body-wave | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.063 · 68 stations |
| 4.0 | mb, body-wave | 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 5.2 km horizontally, 1.9 km in depth
- Magnitude uncertainty
- ±0.06
- Depth from
- Operator assigned
- Station coverage gap
- 110°
- Stations used
- 151
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 6 in the 60 days after this one and 1 in the 30 days before it.
After
- 2.7109 km S of Nikolski, Alaska · 3283 days ago · 36 km deep · 72 km away
- 2.488 km SSE of Nikolski, Alaska · 3273 days ago · 5 km deep · 86 km away
- 4.491 km SE of Nikolski, Alaska · 3263 days ago · 10 km deep · 99 km away
- 3.689 km SE of Nikolski, Alaska · 3254 days ago · 18 km deep · 97 km away
- 2.3101 km SE of Nikolski, Alaska · 3247 days ago · 25 km deep · 85 km away
- 2.4169 km SE of Nikolski, Alaska · 3233 days ago · 45 km deep · 95 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us2000awgp (also filed as ak16941842, ak017ci0ddj3). Read Fri, Oct 2, 2026, 10:06 AM UTC.