[qmarchi]

You're conflating two things, magnitude and intensity.

This earthquake was measured as a 6.9 moment magnitude, sometimes referred to incorrectly as the "Richter" scale.

The Shindo intensity system is measured without decimal places. In this particular case, the intensity was a 6+. Which isn't the highest, but is still quite severe.

[mc3301]

And the Shindo system is best described as "what it feels like at the specific location"

So an earthquake can be a 4 at the epicenter, a 3 a little further away, a 2 even further away, and so on.

Common online conversation with a friend in a different prefecture may be something like, "Last night's earthquake was a 3 here, how about you?"