M4.9 earthquake 113 km ENE of ‘Ohonua, Tonga
A magnitude 4.9 earthquake struck 113 km ENE of ‘Ohonua, Tonga on Thu, Apr 17, 1975, 4:39 AM GMT+13 (15:39 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M5.1 120 km SSE of Pangai, 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
- 1975-04-16 15:39:43 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 20.899° S, 173.958° 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
- 20
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.9 and up: 8 in the 60 days after this one and 2 in the 30 days before it.
After
- 5.1120 km SSE of Pangai, Tonga · 18780 days ago · 40 km deep · 13 km away
- 5.173 km E of ‘Ohonua, Tonga · 18760 days ago · 25 km deep · 66 km away
- 6.0108 km ENE of ‘Ohonua, Tonga · 18754 days ago · 43 km deep · 8 km away
- 4.7121 km SSE of Pangai, Tonga · 18750 days ago · 33 km deep · 17 km away
- 5.5131 km ENE of ‘Ohonua, Tonga · 18749 days ago · 19 km deep · 20 km away
- 5.1118 km SSE of Pangai, Tonga · 18749 days ago · 33 km deep · 17 km away
- 5.064 km S of Pangai, Tonga · 18728 days ago · 39 km deep · 69 km away
- 5.1101 km SSE of Pangai, Tonga · 18728 days ago · 33 km deep · 27 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0000an5. Read Tue, Sep 22, 2026, 8:51 AM UTC.