M5.0 earthquake 173 km S of ‘Ohonua, Tonga
A magnitude 5.0 earthquake struck 173 km S of ‘Ohonua, Tonga on Thu, Aug 22, 1985, 5:15 AM GMT+13 (16:15 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M5.6 Tonga region. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.0 (mb), moderate
- Local time
- UTC
- 1985-08-21 16:15:44 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 22.901° S, 174.896° 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
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.0 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 usp0002hzf. Read Tue, Sep 22, 2026, 3:07 PM UTC.