M5.6 earthquake 151 km W of Neiafu, Tonga
A magnitude 5.6 earthquake struck 151 km W of Neiafu, Tonga on Tue, Nov 6, 1984, 10:44 PM GMT+13 (09:44 UTC), 230 km (143 mi) below the surface.
A larger quake followed: M6.2 183 km W of Neiafu, Tonga. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.6 (Mw, moment), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1984-11-06 09:44:21 UTC
- Depth
- 229.5 km (142.6 mi), intermediate-depth
- Epicenter
- 18.666° S, 175.421° 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 |
|---|---|---|---|
| 5.6 | Mw, moment | USGS National Earthquake Information Center | Preferred · Reviewed |
| 5.61 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.6 | 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.: 12S, 21C Centroid Location: Origin Time 09:44:26.8 0.5 Lat 18.58S 0.06 Lon 175.37W 0.07 Dep 246.7 2.6 Half-duration 2.5 Moment Tensor; Scale 10**24 D-CM Mrr=-1.13 0.11 Mtt=0.85 0.19 Mff=0.28 0.19 Mrt=-0.99 0.15 Mrf=-2.79 0.14 Mtf=0.68 0.18 Principal Axes: (T) Val=3.05 Plg=34 Azm=124 (N) Val=0.29 Plg=12 Azm=25 (P) Val=-3.34 Plg=53 Azm=279 Best Double Couple:Mo=3.2*10**24 NP1:Strike=257 Dip=16 Slip=-37 NP2:Strike=23 Dip=81 Slip=-102
From the USGS event page for usp00028u7. 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 2.6 and up: 6 in the 60 days after this one and 2 in the 30 days before it.
After
- 6.2183 km W of Neiafu, Tonga · 15294 days ago · 33 km deep · 41 km away
- 5.8161 km W of Neiafu, Tonga · 15293 days ago · 230 km deep · 15 km away
- 5.0159 km WNW of Pangai, Tonga · 15289 days ago · 260 km deep · 71 km away
- 4.778 km NNW of Pangai, Tonga · 15280 days ago · 180 km deep · 93 km away
- 4.981 km WSW of Neiafu, Tonga · 15278 days ago · 60 km deep · 79 km away
- 5.188 km NW of Pangai, Tonga · 15268 days ago · 138 km deep · 83 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00028u7 (also filed as gcmtb110684b, gcmt19841106094421, iscgem538474). Read Fri, Oct 2, 2026, 10:26 AM UTC.