10 km W of Onna, Japan

79 days ago

USGS

A magnitude 4.7 earthquake struck 10 km W of Onna, Japan on 21 Aug 2026, 00:01 UTC. The hypocentre was 42.7 km below the surface — shallow by seismological convention.

Depth: 42.7 km
Latitude: 26.50°N
Time: 00:01 UTC
Magnitude: M4.7

EPICENTRE

View the official report↗

MAGNITUDE 4.7

Noticeable shaking of indoor objects. Damage is unlikely.

The scale is logarithmic: this released about 350 times the energy of a magnitude 3.0, roughly the energy of 169 tonnes of TNT.

42.7 KM DEEP

Shallow earthquakes release their energy close to the surface, so they are felt more strongly, and do more damage, than deeper earthquakes of the same magnitude.