M6.1 earthquake 156 km NW of Pangai, Tonga
A magnitude 6.1 earthquake struck 156 km NW of Pangai, Tonga on Mon, Oct 9, 2017, 3:04 AM GMT+13 (14:04 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
- 6.1 (Mww, W-phase moment), strong
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2017-10-08 14:04:38 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 18.990° S, 175.566° W
- Region
- Tonga
- Felt reports
- 1
- 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 |
|---|---|---|---|
| 6.1 | Mww, W-phase moment | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.055 · 32 stations |
| 6.05 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 6.0 | 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
- 142.0% of gravity
- Peak ground velocity
- 1.4 cm/s
- Map
- Automatic
Did you feel it?
1 person reported to the USGS what they felt; the strongest reported shaking was I, not felt 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
- 6.1 Mww
- Nodal plane 1
- Strike 114°, dip 65°, rake -164°
- Nodal plane 2
- Strike 17°, dip 76°, rake -26°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 8.9 km horizontally, 1.8 km in depth
- Magnitude uncertainty
- ±0.06
- Depth from
- Operator assigned
- Station coverage gap
- 80°
- Stations used
- 57
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 3.1 and up: 4 in the 60 days after this one and 4 in the 30 days before it.
After
- 4.6105 km W of Pangai, Tonga · 3251 days ago · 21 km deep · 99 km away
- 4.7140 km W of Neiafu, Tonga · 3243 days ago · 242 km deep · 65 km away
- 4.491 km WNW of Pangai, Tonga · 3235 days ago · 196 km deep · 66 km away
- 4.3125 km W of Pangai, Tonga · 3224 days ago · 223 km deep · 93 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us2000b2sv (also filed as iscgem617824294). Read Thu, Oct 1, 2026, 7:19 AM UTC.