M5.5 earthquake 71 km NNW of Hihifo, Tonga
A magnitude 5.5 earthquake struck 71 km NNW of Hihifo, Tonga on Thu, Feb 20, 2025, 11:31 PM GMT+13 (10:31 UTC), 111 km (69 mi) below the surface.
A larger quake followed: M5.6 81 km WNW of Hihifo, Tonga. This one was a foreshock.
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
- 2025-02-20 10:31:20 UTC
- Depth
- 111.0 km (69.0 mi), intermediate-depth
- Epicenter
- 15.329° S, 173.947° W
- Region
- Tonga
- Felt reports
- 5
- 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 · ±0.065 · 23 stations |
| 5.5 | Mi | NOAA Pacific Tsunami Warning Center | Reviewed · 4 stations |
| 5.6 | Mwb, body-wave moment | USGS National Earthquake Information Center | Moment tensor · Reviewed |
| 5.7 | Mww, W-phase moment | USGS, automatic first solution | First automatic solution · Confirmed |
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
- 2.4% of gravity
- Peak ground velocity
- 1.6 cm/s
- Map
- Automatic

Did you feel it?
5 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
- Oblique normal
- Moment magnitude
- 5.5 Mww
- Nodal plane 1
- Strike 354°, dip 76°, rake -45°
- Nodal plane 2
- Strike 98°, dip 47°, rake -160°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 4.8 km horizontally, 1.9 km in depth
- Magnitude uncertainty
- ±0.07
- Depth from
- From modeling of broad-band P waveforms
- Station coverage gap
- 41°
- Stations used
- 88
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.5 and up: 7 in the 60 days after this one and 9 in the 30 days before it.
After
- 4.683 km NE of Hihifo, Tonga · 583 days ago · 10 km deep · 82 km away
- 4.3102 km NNE of Hihifo, Tonga · 574 days ago · 10 km deep · 49 km away
- 4.497 km NNE of Hihifo, Tonga · 565 days ago · 28 km deep · 52 km away
- 4.594 km WNW of Hihifo, Tonga · 548 days ago · 176 km deep · 71 km away
- 5.681 km WNW of Hihifo, Tonga · 548 days ago · 201 km deep · 65 km away
- 5.393 km NW of Hihifo, Tonga · 548 days ago · 178 km deep · 64 km away
- 5.596 km NNE of Hihifo, Tonga · 533 days ago · 37 km deep · 52 km away · felt by 4
Before
- 4.7149 km NNW of Hihifo, Tonga · 592 days ago · 41 km deep · 82 km away
- 4.5130 km NNE of Hihifo, Tonga · 593 days ago · 10 km deep · 96 km away
- 4.539 km WNW of Hihifo, Tonga · 596 days ago · 82 km deep · 51 km away
- 4.4112 km N of Hihifo, Tonga · 603 days ago · 10 km deep · 56 km away
- 4.5129 km NNE of Hihifo, Tonga · 604 days ago · 10 km deep · 88 km away
- 4.698 km NNW of Hihifo, Tonga · 608 days ago · 10 km deep · 28 km away
- 4.5110 km N of Hihifo, Tonga · 610 days ago · 35 km deep · 46 km away
- 4.523 km WNW of Hihifo, Tonga · 616 days ago · 100 km deep · 60 km away
- 4.589 km WNW of Hihifo, Tonga · 617 days ago · 171 km deep · 74 km away
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us7000pexc (also filed as pt25051000, usauto7000pexc). Read Sun, Oct 4, 2026, 7:04 PM UTC.