M5.7 earthquake 71 km ENE of ‘Ohonua, Tonga
A magnitude 5.7 earthquake struck 71 km ENE of ‘Ohonua, Tonga on Thu, Aug 17, 1978, 9:51 PM GMT+13 (08:51 UTC), 20 km (12 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.7 (mb, body-wave), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1978-08-17 08:51:51 UTC
- Depth
- 20.0 km (12.4 mi), shallow
- Epicenter
- 21.067° S, 174.322° W
- Region
- Tonga
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Magnitude estimates
Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 5.7 | mb, body-wave | USGS National Earthquake Information Center | Preferred · Reviewed |
| 5.95 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.9 | Mwc, centroid moment | Global CMT project | Preliminary |
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
- CONSTRAINED_BY_DEPTH_PHASES
- Stations used
- 111
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.7 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 usp0000w3h (also filed as gcmtb081778b, gcmt19780817085151, iscgem678149). Read Fri, Oct 2, 2026, 1:58 AM UTC.