M5.4 earthquake 131 km SSE of Hihifo, Tonga
A magnitude 5.4 earthquake struck 131 km SSE of Hihifo, Tonga on Thu, Apr 16, 1987, 8:33 PM GMT-12 (08:33 UTC), 33 km (21 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.4 (Mw, moment), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1987-04-17 08:33:36 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 17.095° S, 173.443° 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 |
|---|---|---|---|
| 5.4 | Mw, moment | USGS National Earthquake Information Center | Preferred · Reviewed |
| 5.32 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.3 | Mwc, centroid moment | Global CMT project | Preliminary |
What happened
The USGS’s account of the effects of this earthquake.
CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 13S, 27C Centroid Location: Origin Time 08:33:43.3 0.6 Lat 17.21S 0.12 Lon 173.14W 0.10 Dep 31.8 5.7 Half-duration 1.7 Moment Tensor; Scale 10**17 Nm Mrr=0.38 0.05 Mtt=0.08 0.07 Mff=-0.46 0.06 Mrt=-1.05 0.17 Mrf=0.18 0.12 Mtf=0.43 0.05 Principal Axes: (T) Val=1.30 Plg=48 Azm=172 (N) Val=-0.17 Plg=25 Azm=294 (P) Val=-1.13 Plg=31 Azm=40 Best Double Couple:Mo=1.2*10**17 NP1:Strike=182 Dip=27 Slip=160 NP2:Strike=289 Dip=81 Slip=64
From the USGS event page for usp000347z. 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
- OPERATOR_ASSIGNED
Nearby
Within 100 km, magnitude 2.4 and up: 0 in the 60 days after this one and 2 in the 30 days before it.
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp000347z (also filed as gcmtb041787e, gcmt19870417083336, iscgem469379). Read Fri, Oct 2, 2026, 11:35 PM UTC.