M5.8 earthquake 84 km ESE of ‘Ohonua, Tonga
A magnitude 5.8 earthquake struck 84 km ESE of ‘Ohonua, Tonga on Fri, Feb 18, 1983, 5:10 AM GMT+13 (16:10 UTC), 32 km (20 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.8 (mb, body-wave), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1983-02-17 16:10:39 UTC
- Depth
- 32.0 km (19.9 mi), shallow
- Epicenter
- 21.592° S, 174.179° 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 |
|---|---|---|---|
| 5.8 | mb, body-wave | USGS National Earthquake Information Center | Preferred · Reviewed · 17 stations |
| 5.54 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.5 | Mwc, centroid moment | Global CMT project | Preliminary |
What happened
The USGS’s account of the effects of this earthquake.
CENTROID, MOMENT TENSOR SOLUTION HARVARD EVENT-FILE NAME B021783A DATA USED: GDSN L.P. BODY WAVES: 13S, 33C, T=45 CENTROID LOCATION: ORIGIN TIME 16:10:40.3 0.6 LAT 21.72S 0.05;LON 173.82W 0.05 DEP 10.1 FIX;HALF-DURATION 1.9 MOMENT TENSOR; SCALE 10**24 D-CM MRR=1.51 0.05; MTT=-0.42 0.07 MFF=-1.09 0.07; MRT=0.30 0.19 MRF=2.06 0.20; MTF=-0.82 0.06 PRINCIPAL AXES: 1.(T) VAL=2.65;PLG=61;AZM=264 2.(N) -0.08; 13; 18 3.(P) -2.57; 26; 115 BEST DOUBLE COUPLE:M0=2.6*10**24 NP1:STRIKE=232;DIP=22;SLIP=126 NP2:Strike=14;Dip=72;Slip=77
From the USGS event page for usp0001t48. U.S. Geological Survey text and figures are in the public domain.
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
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.8 and up: 2 in the 60 days after this one and 1 in the 30 days before it.
After
- 5.246 km ESE of ‘Ohonua, Tonga · 15904 days ago · 33 km deep · 38 km away
- 5.2101 km SE of ‘Ohonua, Tonga · 15875 days ago · 33 km deep · 30 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0001t48 (also filed as gcmtb021783a, gcmt19830217161040, iscgem583058). Read Thu, Oct 1, 2026, 10:24 AM UTC.