M6.4 earthquake 91 km SW of Pangai, Tonga
A magnitude 6.4 earthquake struck 91 km SW of Pangai, Tonga on Mon, Dec 24, 2018, 12:08 PM GMT+13 (23:08 UTC), 113 km (70 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 6.4 (mww), strong
- Local time
- UTC
- 2018-12-23 23:08:43 UTC
- Depth
- 113.0 km (70.2 mi), intermediate-depth
- Epicenter
- 20.285° S, 175.071° W
- Region
- Tonga
- Felt reports
- 3
- Strongest shaking
- V, moderate shaking
- PAGER alert
- Green
- Tsunami flag
- Yes: a large quake in an oceanic region
- Status
- Reviewed by a seismologist
Tsunami
The USGS flags a quake this large in an oceanic region. The flag does not mean a tsunami happened; the tsunami warning centers decide that, and their messages are below when they issued any.
Current tsunami warnings: tsunami.gov. Warnings in force in the US also appear on our alerts pages.
Shaking
The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.
- Strongest estimated
- V, moderate shaking
- Peak ground acceleration
- 7.4% of gravity
- Peak ground velocity
- 1.2 cm/s
- Map
- Automatic
Did you feel it?
3 people 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
- Strike-slip
- Moment magnitude
- 6.4 Mww
- Nodal plane 1
- Strike 294°, dip 18°, rake 22°
- Nodal plane 2
- Strike 182°, dip 83°, rake 106°
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 7.8 km horizontally, 1.8 km in depth
- Magnitude uncertainty
- ±0.05
- Depth from
- From modeling of broad-band P waveforms
- Station coverage gap
- 20°
- Stations used
- 706
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 3.4 and up: 6 in the 60 days after this one and 1 in the 30 days before it.
After
- 5.096 km WSW of Pangai, Tonga · 2835 days ago · 78 km deep · 24 km away
- 4.675 km W of Pangai, Tonga · 2834 days ago · 117 km deep · 40 km away
- 4.0Tonga · 2813 days ago · 165 km deep · 36 km away
- 4.868 km NE of Kolonga, Tonga · 2807 days ago · 113 km deep · 58 km away
- 4.9113 km NW of Nuku‘alofa, Tonga · 2805 days ago · 202 km deep · 85 km away
- 4.676 km WNW of Pangai, Tonga · 2788 days ago · 164 km deep · 86 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us2000iwvb (also filed as pt18357001, at00pk7pmi, iscgem615091897). Read Sun, Sep 27, 2026, 8:38 PM UTC.