M4.3 earthquake 20 km E of Gero, Japan
A magnitude 4.3 earthquake struck 20 km E of Gero, Japan on Sat, Sep 15, 1984, 9:05 AM JST (00:05 UTC), 5 km (3 mi) below the surface.
A larger quake followed: M5.1 30 km E of Gero, Japan. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.3 (mb, body-wave), light
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1984-09-15 00:05:45 UTC
- Depth
- 4.5 km (2.8 mi), shallow
- Epicenter
- 35.778° N, 137.453° E
- Region
- Japan
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
What happened
The USGS’s account of the effects of this earthquake.
Felt (III JMA) at Iida, (I JMA) at Nagoya, Yokohama and Tokyo.
From the USGS event page for usp00027dd. 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.
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 1 in the 60 days after this one and 6 in the 30 days before it.
After
Before
- 5.017 km E of Gero, Japan · 15359 days ago · 10 km deep · 3 km away
- 5.717 km E of Gero, Japan · 15359 days ago · 10 km deep · 3 km away
- 4.417 km E of Gero, Japan · 15360 days ago · 10 km deep · 4 km away
- 4.933 km ENE of Gero, Japan · 15360 days ago · 10 km deep · 18 km away
- 6.223 km E of Gero, Japan · 15360 days ago · 10 km deep · 3 km away
- 4.626 km E of Katsuyama, Japan · 15387 days ago · 279 km deep · 68 km away
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Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp00027dd. Read Sat, Oct 3, 2026, 10:44 PM UTC.