By the context, it seems to me like 弱 is a counter for degrees on the richter scale (and perhaps other things). Am I getting this wrong? So that’s the first question.
On the second question: It seems to me like a weird kanji for counting earthquake strength. Maybe the richter scale being logarithmic has something to do with it. That would make it weak in a sense (compared to a linear scale).
If anyone could shed some light on this, I would appreciate it.
So the weak/strong only applies for 5+ on the scale. I’m guessing the scale is still logarithmic, so higher values need the differentiation between stronger and weaker (I haven’t read too much into it).
On an almost completely unrelated note, we don’t use the Richter scale in the West either, not any more. We use the Moment Magnitude Scale (which is fairly close to Richter in the middle ranges, to be fair, but it’s more accurate).
The answer I was fishing for was if 震度 was primarily one or the other. But it was an unnecessary question. If it’s both, then it doesn’t really matter.
The interesting thing about the Shindo scale for me is that because it measures how intensely the shaking is felt at the surface, the measurement will be different depending on how far away from the epicenter you are. So if you look at the map from the article:
The epicenter is marked with an X, and the area directly next to it felt the quake as a lower 5. Then we can see that the next island to the right felt it as a 3, whereas the two islands further out only felt it as a 2.