M5.5 earthquake 65 km SSE of Hihifo, Tonga
A magnitude 5.5 earthquake struck 65 km SSE of Hihifo, Tonga on Fri, Apr 28, 2017, 7:46 AM GMT+13 (18:46 UTC), 59 km (37 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.5 (Mww, W-phase moment), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 2017-04-27 18:46:45 UTC
- Depth
- 59.0 km (36.7 mi), shallow
- Epicenter
- 16.530° S, 173.646° 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 |
|---|---|---|---|
| 5.5 | Mww, W-phase moment | USGS National Earthquake Information Center | Preferred · Reviewed · ±0.083 · 14 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 |
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?
1 person reported to the USGS what they felt; the strongest reported shaking was II, 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
- Oblique reverse
- Moment magnitude
- 5.5 Mww
- Nodal plane 1
- Strike 159°, dip 55°, rake 137°
- Nodal plane 2
- Strike 277°, dip 56°, rake 44°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 8.6 km horizontally, 1.9 km in depth
- Magnitude uncertainty
- ±0.08
- Depth from
- Operator assigned
- Station coverage gap
- 27°
- Stations used
- 569
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.5 and up: 8 in the 60 days after this one and 6 in the 30 days before it.
After
- 4.5110 km SE of Hihifo, Tonga · 3443 days ago · 10 km deep · 67 km away
- 4.3111 km SSW of Hihifo, Tonga · 3428 days ago · 148 km deep · 76 km away
- 4.993 km SSE of Hihifo, Tonga · 3428 days ago · 22 km deep · 28 km away
- 4.4108 km SSW of Hihifo, Tonga · 3422 days ago · 95 km deep · 68 km away
- 5.3132 km SSE of Hihifo, Tonga · 3420 days ago · 10 km deep · 68 km away
- 4.567 km S of Hihifo, Tonga · 3419 days ago · 73 km deep · 26 km away
- 4.5114 km SSE of Hihifo, Tonga · 3401 days ago · 23 km deep · 54 km away
- 4.9109 km SSE of Hihifo, Tonga · 3389 days ago · 138 km deep · 44 km away
Before
- 4.425 km SSE of Hihifo, Tonga · 3446 days ago · 86 km deep · 42 km away
- 4.925 km SSE of Hihifo, Tonga · 3448 days ago · 66 km deep · 42 km away
- 4.536 km ESE of Hihifo, Tonga · 3453 days ago · 129 km deep · 48 km away
- 5.119 km SSW of Hihifo, Tonga · 3455 days ago · 97 km deep · 50 km away
- 4.693 km E of Hihifo, Tonga · 3464 days ago · 35 km deep · 99 km away
- 4.516 km SSE of Hihifo, Tonga · 3474 days ago · 110 km deep · 49 km away
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us10008ld1 (also filed as iscgem610570307). Read Fri, Oct 2, 2026, 11:25 AM UTC.