M5.3 earthquake 151 km SW of Vailoatai, American Samoa
A magnitude 5.3 earthquake struck 151 km SW of Vailoatai, American Samoa on Tue, Aug 22, 2017, 10:12 AM GMT+13 (21:12 UTC), 10 km (6 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.3 (Mww, W-phase moment), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2017-08-21 21:12:23 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 15.493° S, 171.576° W
- Region
- American Samoa
- Felt reports
- 3
- 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 |
|---|---|---|---|
| 5.3 | Mww, W-phase moment | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.078 · 16 stations |
| 5.3 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.4 | Mi | NOAA Pacific Tsunami Warning Center | Reviewed · 62 stations |
Did you feel it?
3 people reported to the USGS what they felt; the strongest reported shaking was III, weak shaking.
Fault motion and ground failure
How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.
- Faulting
- Oblique normal
- Moment magnitude
- 5.3 Mww
- Nodal plane 1
- Strike 206°, dip 22°, rake -58°
- Nodal plane 2
- Strike 352°, dip 71°, rake -102°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 7.3 km horizontally, 1.8 km in depth
- Magnitude uncertainty
- ±0.08
- Depth from
- Operator assigned
- Station coverage gap
- 72°
- Stations used
- 114
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.3 and up: 1 in the 60 days after this one and 1 in the 30 days before it.
After
Before
Earthquakes todayAmerican Samoa earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us2000aaei (also filed as pt17233050, iscgem616640300). Read Sat, Oct 3, 2026, 1:19 AM UTC.