M5.6 earthquake 235 km NNE of Colonia, Micronesia
A magnitude 5.6 earthquake struck 235 km NNE of Colonia, Micronesia on Wed, Jul 11, 1984, 11:40 AM GMT+9 (02:40 UTC), 45 km (28 mi) below the surface.
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
- 1984-07-11 02:40:44 UTC
- Depth
- 44.5 km (27.7 mi), shallow
- Epicenter
- 11.492° N, 138.917° E
- Region
- Micronesia
- 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 |
| 5.54 | 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 (HRV) Data Used: GDSN L.P.B.: 12S, 24C Centroid Location: Origin Time 02:40:48.2 0.3 Lat 11.62N 0.04 Lon 139.04E 0.07 Dep 28.1 3.4 Half-duration 2.2 Moment Tensor; Scale 10**24 D-CM Mrr=2.19 0.12 Mtt=-1.47 0.12 Mff=-0.73 0.20 Mrt=-0.32 0.23 Mrf=0.44 0.21 Mtf=-1.51 0.09 Principal Axes: (T) Val=2.35 Plg=74 Azm=233 (N) Val=0.30 Plg=16 Azm=52 (P) Val=-2.65 Plg=0 Azm=142 Best Double Couple:Mo=2.5*10**24 NP1:Strike=247 Dip=47 Slip=112 NP2:Strike=37 Dip=47 Slip=68
From the USGS event page for usp00025ng. 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.
Nearby
Within 100 km, magnitude 2.6 and up: 1 in the 60 days after this one and 0 in the 30 days before it.
After
Earthquakes todayMicronesia earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00025ng (also filed as gcmtb071184a, gcmt19840711024042, iscgem548746). Read Mon, Oct 5, 2026, 5:20 AM UTC.