M5.6 earthquake Tonga region
A magnitude 5.6 earthquake struck in the Tonga region on Fri, Aug 23, 1985, 8:29 AM GMT+13 (19:29 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M6.1 99 km SSE of ‘Ohonua, Tonga. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.6 (mw), moderate
- Local time
- UTC
- 1985-08-22 19:29:58 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 22.364° S, 174.733° 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 2.6 and up: 2 in the 60 days after this one and 1 in the 30 days before it.
After
- 6.199 km SSE of ‘Ohonua, Tonga · 14975 days ago · 33 km deep · 25 km away
- 5.2128 km SSE of ‘Ohonua, Tonga · 14961 days ago · 33 km deep · 35 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0002j0z (also filed as gcmtb082285b, gcmt19850822192957, iscgem518672). Read Sun, Sep 27, 2026, 1:59 AM UTC.