M6.0 earthquake 191 km NW of Hihifo, Tonga
A magnitude 6.0 earthquake struck 191 km NW of Hihifo, Tonga on Tue, Nov 21, 2017, 8:51 AM GMT+14 (18:51 UTC), 9 km (6 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 6.0 (Mww, W-phase moment), strong
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2017-11-20 18:51:07 UTC
- Depth
- 9.0 km (5.6 mi), shallow
- Epicenter
- 14.724° S, 175.048° W
- Region
- Tonga
- Felt reports
- 2
- Strongest shaking
- IV, light shaking
- PAGER alert
- Green
- 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 |
|---|---|---|---|
| 6.0 | Mww, W-phase moment | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.075 · 17 stations |
| 5.98 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 6.2 | Mi | NOAA Pacific Tsunami Warning Center | Reviewed · 3 stations |
| 5.9 | Mwb, body-wave moment | USGS National Earthquake Information Center | Moment tensor · Reviewed |
Shaking
The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.
- Strongest estimated
- IV, light shaking
- Peak ground acceleration
- 122.0% of gravity
- Peak ground velocity
- 1.5 cm/s
- Map
- Automatic
Did you feel it?
2 people reported to the USGS what they felt; the strongest reported shaking was III, weak shaking.
Estimated impact
The USGS PAGER system estimates deaths and economic losses from the shaking and the population and buildings exposed to it.
- Alert level
- Green: little or no damage or loss of life expected
| Range | Chance |
|---|---|
| Under 1 | 65% |
| 1 to 10 | 30% |
| 10 to 100 | 4% |
| 100 to 1,000 | Under 1% |
| 1,000 to 10,000 | Under 1% |
| 10,000 to 100,000 | Under 1% |
| 100,000 to 10,000,000 | Under 1% |
| Range, million USD | Chance |
|---|---|
| Under 1 | 65% |
| 1 to 10 | 30% |
| 10 to 100 | 4% |
| 100 to 1,000 | Under 1% |
| 1,000 to 10,000 | Under 1% |
| 10,000 to 100,000 | Under 1% |
| 100,000 to 10,000,000 | Under 1% |
Fault motion and ground failure
How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.
- Faulting
- Strike-slip
- Moment magnitude
- 6.0 Mww
- Nodal plane 1
- Strike 93°, dip 68°, rake -9°
- Nodal plane 2
- Strike 186°, dip 82°, rake -157°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 8.4 km horizontally, 1.7 km in depth
- Magnitude uncertainty
- ±0.07
- Depth from
- Operator assigned
- Station coverage gap
- 42°
- Stations used
- 134
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 3.0 and up: 1 in the 60 days after this one and 0 in the 30 days before it.
After
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us2000brz0 (also filed as pt17324001, iscgem615212201). Read Fri, Oct 2, 2026, 3:24 PM UTC.