M5.5 earthquake 118 km SW of Houma, Tonga
A magnitude 5.5 earthquake struck 118 km SW of Houma, Tonga on Sat, Aug 17, 2024, 4:29 PM GMT+13 (03:29 UTC), 123 km (76 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
- 2024-08-17 03:29:16 UTC
- Depth
- 122.6 km (76.2 mi), intermediate-depth
- Epicenter
- 21.831° S, 176.201° 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 · ±0.073 · 18 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 · 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
- 1.4% of gravity
- Peak ground velocity
- 1.0 cm/s
- Map
- Automatic
Did you feel it?
1 person 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
- Normal
- Moment magnitude
- 5.5 Mww
- Nodal plane 1
- Strike 9°, dip 85°, rake -99°
- Nodal plane 2
- Strike 253°, dip 11°, rake -27°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 8.8 km horizontally, 4.1 km in depth
- Magnitude uncertainty
- ±0.07
- Depth from
- From location
- Station coverage gap
- 44°
- Stations used
- 102
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.5 and up: 3 in the 60 days after this one and 1 in the 30 days before it.
After
- 4.689 km WSW of Houma, Tonga · 766 days ago · 137 km deep · 34 km away
- 4.4126 km SSW of ‘Ohonua, Tonga · 757 days ago · 10 km deep · 87 km away
- 4.2169 km SSW of Houma, Tonga · 750 days ago · 72 km deep · 74 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us7000n7kb (also filed as usauto7000n7kb). Read Sun, Oct 4, 2026, 11:22 AM UTC.