Japan earthquakes

M8.0 earthquake 5 km SSE of ?iso, Japan

A magnitude 8.0 earthquake struck 5 km SSE of ?iso, Japan on Sat, Sep 1, 1923, 11:58 AM JST (02:58 UTC), 15 km (9 mi) below the surface.

Ōiso forecast More in Japan

Map

Where this earthquake was located, with the others nearby. Select one for its page.

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The earthquake

Magnitude: 8.0 (mw), major
Local time: Sat, Sep 1, 1923, 11:58 AM JST
UTC: 1923-09-01 02:58:35 UTC
Depth: 15.0 km (9.3 mi), shallow
Epicenter: 35.274° N, 139.344° E
Region: Japan
Strongest shaking: IX, violent shaking
Tsunami flag: No
Status: Reviewed by a seismologist

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated: IX, violent shaking
Peak ground acceleration: 97.8% of gravity
Peak ground velocity: 86.0 cm/s
Map: Automatic

USGS ShakeMap: estimated shaking intensity around the epicenter — Estimated shaking intensity. Map: USGS ShakeMap.

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: Red
Liquefaction alert: Red

How well it is located

Reviewed by a seismologist.

Magnitude uncertainty: ±0.30
Depth from: From location

Nearest places

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

Nearby

Within 100 km, magnitude 2.5 and up: 6 in the 60 days after this one and 0 in the 30 days before it.

After

Earthquakes today Japan earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event iscgem911526 (also filed as atlas19230901025800, atlas19230901025837). Read Tue, Sep 22, 2026, 4:25 PM UTC.