M3.3 earthquake 199 km SSE of Unalaska, Alaska
A magnitude 3.3 earthquake struck 199 km SSE of Unalaska, Alaska on Wed, Oct 17, 2018, 12:32 PM AKDT (20:32 UTC), 25 km (16 mi) below the surface.
A larger quake followed: M3.7 129 km SSE of Unalaska, Alaska. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 3.3 (ML, local (Richter)), minor
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2018-10-17 20:32:04 UTC
- Depth
- 25.2 km (15.6 mi), shallow
- Epicenter
- 52.253° N, 165.248° 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 |
|---|---|---|---|
| 3.3 | ML, local (Richter) | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.128 · 8 stations |
| 3.1 | 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 8.9 km horizontally, 22.2 km in depth
- Magnitude uncertainty
- ±0.13
- Depth from
- From location
- Station coverage gap
- 223°, poorly surrounded by stations
- Stations used
- 27
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 5 in the 60 days after this one and 4 in the 30 days before it.
After
- 2.3183 km SSE of Unalaska, Alaska · 2892 days ago · 34 km deep · 19 km away
- 3.7129 km SSE of Unalaska, Alaska · 2879 days ago · 15 km deep · 73 km away
- 3.4147 km SSE of Akutan, Alaska · 2865 days ago · 10 km deep · 99 km away
- 2.5155 km SE of Akutan, Alaska · 2865 days ago · 9 km deep · 97 km away
- 2.7149 km S of Unalaska, Alaska · 2864 days ago · 21 km deep · 89 km away
Before
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us1000hdnz (also filed as ak20285928, ak018dbxy6m1). Read Thu, Oct 1, 2026, 4:21 AM UTC.