M4.9 earthquake 177 km WNW of Hihifo, Tonga
A magnitude 4.9 earthquake struck 177 km WNW of Hihifo, Tonga on Sat, Mar 17, 1973, 3:31 PM GMT-11 (02:31 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M5.1 220 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
- 4.9 (mb), light
- Local time
- UTC
- 1973-03-18 02:31:32 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 15.084° S, 175.182° 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.
- Depth from
- OPERATOR_ASSIGNED
- Stations used
- 13
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.9 and up: 1 in the 60 days after this one and 1 in the 30 days before it.
After
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00000zf. Read Tue, Sep 22, 2026, 3:59 PM UTC.