M4.1 earthquake 154 km SE of Chignik, Alaska
A magnitude 4.1 earthquake struck 154 km SE of Chignik, Alaska on Fri, Aug 18, 2017, 11:36 PM AKDT (07:36 UTC), 37 km (23 mi) below the surface.
A larger quake followed: M4.9 247 km SE of Chignik, Alaska. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.1 (ML, local (Richter)), light
- Magnitude from
- Alaska Earthquake Center
- Local time
- UTC
- 2017-08-19 07:36:41 UTC
- Depth
- 37.3 km (23.2 mi), shallow
- Epicenter
- 55.248° N, 156.778° 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 |
|---|---|---|---|
| 4.1 | ML, local (Richter) | Alaska Earthquake Center | Preferred · Preliminary |
| 4.3 | Mwr, regional moment | USGS National Earthquake Information Center | Reviewed · ±0.039 · 62 stations |
Did you feel it?
No one has reported feeling this quake to the USGS.
Fault motion and ground failure
How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.
- Faulting
- Normal
- Moment magnitude
- 4.3 Mwr
- Nodal plane 1
- Strike 235°, dip 86°, rake -113°
- Nodal plane 2
- Strike 135°, dip 23°, rake -10°
How well it is located
Reviewed by a seismologist.
- Stations used
- 98
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 11 in the 60 days after this one and 2 in the 30 days before it.
After
- 2.293 km SE of Chignik, Alaska · 3311 days ago · 22 km deep · 62 km away
- 2.375 km SE of Perryville, Alaska · 3311 days ago · 19 km deep · 95 km away
- 4.4149 km SSE of Chignik, Alaska · 3311 days ago · 37 km deep · 23 km away
- 2.3163 km SE of Chignik, Alaska · 3309 days ago · 12 km deep · 14 km away
- 4.6147 km SE of Chignik, Alaska · 3308 days ago · 8 km deep · 19 km away
- 4.1149 km SSE of Chignik, Alaska · 3308 days ago · 23 km deep · 21 km away
- 3.495 km ESE of Chignik, Alaska · 3304 days ago · 45 km deep · 85 km away
- 3.2215 km SE of Perryville, Alaska · 3286 days ago · 12 km deep · 81 km away
- 4.0south of Alaska · 3284 days ago · 12 km deep · 87 km away
- 4.0215 km SE of Perryville, Alaska · 3284 days ago · 10 km deep · 78 km away
- 4.9247 km SE of Chignik, Alaska · 3278 days ago · 3 km deep · 92 km away · felt by 1
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event ak017am5j09c (also filed as ak16570115, us2000a9q0). Read Sat, Oct 3, 2026, 9:24 AM UTC.