M5.5 earthquake 96 km NNE of Hihifo, Tonga
A magnitude 5.5 earthquake struck 96 km NNE of Hihifo, Tonga on Sun, Apr 20, 2025, 5:55 AM GMT+13 (16:55 UTC), 37 km (23 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
- 2025-04-19 16:55:05 UTC
- Depth
- 36.9 km (22.9 mi), shallow
- Epicenter
- 15.132° S, 173.508° W
- Region
- Tonga
- Felt reports
- 4
- 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 · ±0.11 · 8 stations |
| 5.5 | Mww, W-phase moment | USGS, automatic first solution | First automatic solution · Preliminary |
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
- 1.6% of gravity
- Peak ground velocity
- 1.3 cm/s
- Map
- Automatic
Did you feel it?
4 people reported to the USGS what they felt; the strongest reported shaking was IV, light 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 99°, dip 82°, rake -49°
- Nodal plane 2
- Strike 198°, dip 41°, rake -169°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 9.6 km horizontally, 4.8 km in depth
- Magnitude uncertainty
- ±0.11
- Depth from
- From location
- Station coverage gap
- 43°
- Stations used
- 189
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 0 in the 30 days before it.
After
- 4.3143 km SSW of Gataivai, Samoa · 530 days ago · 10 km deep · 82 km away
- 4.978 km NNW of Hihifo, Tonga · 526 days ago · 59 km deep · 52 km away
- 4.599 km NNW of Hihifo, Tonga · 524 days ago · 68 km deep · 59 km away
- 4.4133 km SW of Gataivai, Samoa · 517 days ago · 10 km deep · 61 km away
- 4.336 km NNW of Hihifo, Tonga · 512 days ago · 65 km deep · 70 km away
- 4.693 km NE of Hihifo, Tonga · 504 days ago · 10 km deep · 32 km away
- 4.3112 km NNE of Hihifo, Tonga · 491 days ago · 10 km deep · 18 km away
- 4.632 km NNE of Hihifo, Tonga · 474 days ago · 55 km deep · 65 km away
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us6000q78n (also filed as usauto6000q78n). Read Mon, Oct 5, 2026, 2:55 AM UTC.