M4.2 earthquake 257 km W of Hihifo, Tonga
A magnitude 4.2 earthquake struck 257 km W of Hihifo, Tonga on Sun, Aug 15, 2021, 7:39 PM GMT-12 (07:39 UTC), 361 km (224 mi) below the surface.
A larger quake followed: M4.6 161 km W 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
- 4.2 (mb), light
- Local time
- UTC
- 2021-08-16 07:39:09 UTC
- Depth
- 360.7 km (224.1 mi), deep
- Epicenter
- 16.020° S, 176.197° W
- Region
- Tonga
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Did you feel it?
No one has reported feeling this quake to the USGS.
How well it is located
Reviewed by a seismologist.
- Location uncertainty
- About 10.5 km horizontally, 7.2 km in depth
- Magnitude uncertainty
- ±0.15
- Depth from
- From location
- Station coverage gap
- 116°
- Stations used
- 17
Nearby
Within 100 km, magnitude 1.5 and up: 4 in the 60 days after this one and 0 in the 30 days before it.
After
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us7000f4n0. Read Wed, Sep 30, 2026, 1:48 PM UTC.