M4.2 earthquake 230 km WSW of Hihifo, Tonga
A magnitude 4.2 earthquake struck 230 km WSW of Hihifo, Tonga on Fri, Aug 20, 2021, 10:01 PM GMT-12 (10:01 UTC), 346 km (215 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
- 2021-08-21 10:01:46 UTC
- Depth
- 345.9 km (214.9 mi), deep
- Epicenter
- 16.401° S, 175.898° 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 7.1 km horizontally, 12.6 km in depth
- Magnitude uncertainty
- ±0.11
- Depth from
- From location
- Station coverage gap
- 114°
- Stations used
- 27
Nearby
Within 100 km, magnitude 1.5 and up: 3 in the 60 days after this one and 2 in the 30 days before it.
After
- 4.0Fiji region · 1846 days ago · 380 km deep · 73 km away
- 4.4141 km W of Hihifo, Tonga · 1838 days ago · 222 km deep · 89 km away
- 4.6161 km W of Hihifo, Tonga · 1835 days ago · 321 km deep · 85 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event us7000f6n2. Read Wed, Sep 30, 2026, 11:30 AM UTC.