M5.7 earthquake 181 km NW of Neiafu, Tonga
A magnitude 5.7 earthquake struck 181 km NW of Neiafu, Tonga on Sat, Apr 25, 1987, 7:50 PM GMT-12 (07:50 UTC), 279 km (173 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.7 (Mw, moment), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1987-04-26 07:50:53 UTC
- Depth
- 279.1 km (173.4 mi), intermediate-depth
- Epicenter
- 17.288° S, 174.944° 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 | Mw, moment | USGS National Earthquake Information Center | Preferred · Reviewed |
| 5.72 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.7 | 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.: 18S, 41C Centroid Location: Origin Time 07:50:59.0 0.4 Lat 17.05S 0.03 Lon 174.74W 0.03 Dep 277.4 1.4 Half-duration 2.8 Moment Tensor; Scale 10**17 Nm Mrr=-4.03 0.09 Mtt=4.92 0.16 Mff=-0.89 0.17 Mrt=0.13 0.15 Mrf=-1.13 0.15 Mtf=-0.03 0.14 Principal Axes: (T) Val=4.92 Plg=1 Azm=0 (N) Val=-0.53 Plg=18 Azm=91 (P) Val=-4.39 Plg=72 Azm=268 Best Double Couple:Mo=4.7*10**17 NP1:Strike=73 Dip=47 Slip=-115 NP2:Strike=287 Dip=49 Slip=-66
From the USGS event page for usp00034g2. 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
Nearby
Within 100 km, magnitude 2.7 and up: 1 in the 60 days after this one and 2 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 usp00034g2 (also filed as gcmtb042687b, gcmt19870426075054, iscgem469999). Read Thu, Oct 1, 2026, 12:50 PM UTC.