Japan earthquakes

M4.2 earthquake 51 km E of Iwaki, Japan

A magnitude 4.2 earthquake struck 51 km E of Iwaki, Japan on Sat, Sep 9, 1978, 8:59 PM JST (11:59 UTC), 80 km (50 mi) below the surface.

A larger quake followed: M4.5 70 km ESE of Namie, Japan. This one was a foreshock.

Iwaki forecastMore in Japan

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The earthquake

Magnitude
4.2 (mb), light
Local time
UTC
1978-09-09 11:59:44 UTC
Depth
80.0 km (49.7 mi), intermediate-depth
Epicenter
37.071° N, 141.461° E
Region
Japan
Tsunami flag
No
Status
Reviewed by a seismologist

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Stations used
32

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nearby

Within 100 km, magnitude 1.5 and up: 3 in the 60 days after this one and 0 in the 30 days before it.

After

Earthquakes todayJapan earthquakesLive radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event usp0000wfd. Read Tue, Sep 22, 2026, 11:17 AM UTC.