M5.7 earthquake 17 km E of Gero, Japan
A magnitude 5.7 earthquake struck 17 km E of Gero, Japan on Sat, Sep 15, 1984, 7:14 AM JST (22:14 UTC), 10 km (6 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
- 1984-09-14 22:14:31 UTC
- Depth
- 10.0 km (6.2 mi), shallow
- Epicenter
- 35.774° N, 137.424° E
- Region
- Japan
- Strongest shaking
- VII, very strong shaking
- 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 |
| 5.68 | 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.
Felt (III JMA) in the Chichibu-Nagoya area and (II JMA) at Chiba, Kyoto, Osaka and Tokyo. Also felt in northern Honshu and on Kyushu. CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 13S, 28C Centroid Location: Origin Time 22:14:35.5 0.3 Lat 35.82N 0.04 Lon 137.49E 0.06 Dep 15.6 2.8 Half-duration 2.6 Moment Tensor; Scale 10**24 D-CM Mrr=1.50 0.10 Mtt=1.52 0.09 Mff=-3.02 0.15 Mrt=-2.31 0.45 Mrf=0.83 0.31 Mtf=-2.02 0.08 Principal Axes: (T) Val=4.38 Plg=40 Azm=201 (N) Val=-0.59 Plg=50 Azm=22 (P) Val=-3.79 Plg=1 Azm=291 Best Double Couple:Mo=4.1*10**24 NP1:Strike=344 Dip=62 Slip=31 NP2:Strike=238 Dip=63 Slip=148
From the USGS event page for usp00027d9. U.S. Geological Survey text and figures are in the public domain.
Shaking
The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.
- Strongest estimated
- VII, very strong shaking
- Peak ground acceleration
- 26.9% of gravity
- Peak ground velocity
- 2.9 cm/s
- Map
- Automatic
Did you feel it?
No one has reported feeling this quake to the USGS.
Fault motion and ground failure
How the rock slipped, from the moment tensor, and the USGS estimate of landslides and liquefaction.
- Landslide alert
- Green
- Liquefaction alert
- Green
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 2.7 and up: 3 in the 60 days after this one and 4 in the 30 days before it.
After
- 5.017 km E of Gero, Japan · 15360 days ago · 10 km deep · 0 km away
- 4.320 km E of Gero, Japan · 15360 days ago · 5 km deep · 3 km away
- 5.130 km E of Gero, Japan · 15342 days ago · 15 km deep · 14 km away
Before
Earthquakes todayJapan earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00027d9 (also filed as gcmtb091484a, gcmt19840914221432, atlas19840914221431, iscgem544015). Read Sun, Oct 4, 2026, 11:54 PM UTC.