M5.6 earthquake 112 km SE of Pangai, Tonga
A magnitude 5.6 earthquake struck 112 km SE of Pangai, Tonga on Fri, Apr 21, 2017, 11:59 AM GMT+13 (22:59 UTC), 13 km (8 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.6 (Mww, W-phase moment), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2017-04-20 22:59:24 UTC
- Depth
- 13.0 km (8.1 mi), shallow
- Epicenter
- 20.542° S, 173.602° W
- Region
- Tonga
- 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 |
|---|---|---|---|
| 5.6 | Mww, W-phase moment | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.073 · 18 stations |
| 5.53 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.5 | Mwb, body-wave moment | USGS National Earthquake Information Center | Moment tensor · Reviewed |
What happened
The USGS’s account of the effects of this earthquake.
dd
From the USGS event page for us10008jeq. U.S. Geological Survey text and figures are in the public domain.
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
- Map
- Automatic
Did you feel it?
No one has reported feeling this quake to the USGS.
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
- Reverse (thrust)
- Moment magnitude
- 5.6 Mww
- Nodal plane 1
- Strike 172°, dip 32°, rake 73°
- Nodal plane 2
- Strike 12°, dip 60°, rake 100°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 7.3 km horizontally, 1.7 km in depth
- Magnitude uncertainty
- ±0.07
- Depth from
- From modeling of broad-band P waveforms
- Station coverage gap
- 38°
- Stations used
- 426
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.6 and up: 7 in the 60 days after this one and 1 in the 30 days before it.
After
- 5.3103 km SE of Pangai, Tonga · 3450 days ago · 10 km deep · 9 km away
- 4.9128 km ESE of Pangai, Tonga · 3449 days ago · 10 km deep · 38 km away
- 4.9113 km ESE of Pangai, Tonga · 3446 days ago · 10 km deep · 52 km away
- 5.1131 km ESE of Pangai, Tonga · 3435 days ago · 10 km deep · 39 km away
- 4.586 km E of Pangai, Tonga · 3435 days ago · 10 km deep · 66 km away
- 4.536 km E of Pangai, Tonga · 3426 days ago · 14 km deep · 91 km away
- 4.8101 km E of Pangai, Tonga · 3412 days ago · 10 km deep · 94 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us10008jeq (also filed as iscgem611833495). Read Mon, Oct 5, 2026, 2:40 AM UTC.