[matthewmacleod]

The Richter scale measures and describes impacts, so you already know the impact from the 6.4 rating itself.

I'm sorry, this is not quite true. The Richter scale measures the amplitude of seismic waves; the description you highlight is what might be expected generally, but doesn't give us any indication of the actual on-the-ground impact that any particular quake might have.

[haylem]

You're right, and my grammar was indeed incorrect: I did not mean to say that it measure the impacts but instead that it measures the amplitude of the quake, and also describes the impacts (which may or may not originally be true, but is how I've always seen it taught in classrooms, at least where I'm from). I guess I did remember it being closer to the model of the Beaufort scale for wind strength (which is more about the description than an actual measure of speed, originally).

And of course it does not give a precise description of the actual impacts for a given event, but I don't think it's generally far off the bat. But I'm no seismologist.

[zzleeper]

It doesn't measure the impact. For instance, 7.0 earthquakes can have a vastly different effect depending on the depth of the epicenter, the length of the earthquake, proximity to populated areas, proximity to faults.

EG:

https://apnews.com/d4217c33c5124972845022441d69728c