M6.5 earthquake 297 km NW of Haveluloto, Tonga
A magnitude 6.5 earthquake struck 297 km NW of Haveluloto, Tonga on Tue, Feb 10, 1987, 1:59 PM GMT+13 (00:59 UTC), 395 km (245 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 6.5 (Mw, moment), strong
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1987-02-10 00:59:28 UTC
- Depth
- 394.5 km (245.1 mi), deep
- Epicenter
- 19.489° S, 177.456° 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 |
|---|---|---|---|
| 6.5 | Mw, moment | USGS National Earthquake Information Center | Preferred · Reviewed |
| 6.45 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 6.4 | Mwc, centroid moment | Global CMT project | Preliminary |
| 6.31 | Me, energy | Choy, USGS energy magnitude | Reviewed |
What happened
The USGS’s account of the effects of this earthquake.
Depth from broadband displacement seismograms. FAULT PLANE SOLUTION: P-Waves NP1:Strike=10 Dip=77 Slip=-90 NP2:Strike=190 Dip=13 Slip=-90 Principal Axes: (T) Plg=32 Azm=100 (P) Plg=58 Azm=280 Comment: The focal mechanism is poorly controlled and corresponds to normal faulting. The preferred fault plane is NP1. RADIATED ENERGY No. of sta: 6 Focal mech. C Energy 7.4+1.7*10**13 Nm MOMENT TENSOR SOLUTION Dep 391 No. of sta: 9 Moment Tensor; Scale 10**18 Nm Mrr=-2.19 Mtt=-0.75 Mff=2.94 Mrt=-0.57 Mrf=-5.09 Mtf=-2.03 Principal axes: (T) Val=6.37 Plg=29 Azm=77 (N) Val=-0.55 Plg=21 Azm=179 (P) Val=-5.81 Plg=52 Azm=300 Best Double Couple:Mo=6.1*10**18 NP1:Strike=122 Dip=25 Slip=-150 NP2:Strike=4 Dip=78 Slip=-68 CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN, IDA L.P.B.: 20S, 51C M.W.: 13S, 29C Centroid Location: Origin Time 00:59:35.9 0.1 Lat 19.47S 0.01 Lon 177.38W 0.01 Dep 418.5 0.6 Half-duration 6.4 Moment Tensor; Scale 10**18 Nm Mrr=-3.09 0.04 Mtt=-0.57 0.06 Mff=3.67 0.06 Mrt=-1.06 0.05 Mrf=-4.60 0.06 Mtf=-0.09 0.05 Principal Axes: (T) Val=6.02 Plg=27 Azm=94 (N) Val=-0.41 Plg=8 Azm=188 (P) Val=-5.61 Plg=61 Azm=294 Best Double Couple:Mo=5.8*10**18 NP1:Strike=164 Dip=19 Slip=-116 NP2:Strike=11 Dip=73 Slip=-81
From the USGS event page for usp00032bc. 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
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 3.5 and up: 0 in the 60 days after this one and 0 in the 30 days before it.
None recorded.
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00032bc (also filed as choy19870210005928, gcmtc021087a, gcmt19870210005929, iscgem474211). Read Thu, Oct 1, 2026, 4:22 PM UTC.