Roger, I was interested enough that I used Excel to make a graph for the first time (Your FFA data). Canie, how do I send it to you to post? What graphics format?
There certainly is a big peak at 101 to 102 deg-Lowell claims 102-close enough. There are some peaks at some of the other distances, and some at distances not mentioned. There are not peaks at some of the smaller distances, and, surprisingly, none at the antipode (there would be a peak near the antipode for M7s in 1927....). This is interesting enough that perhaps you would want to run this again for all quakes larger than M7 rather than M7.5. Perhaps exlude quakes >7.5-just use M7 to 7.5. The reason to exclude >7.5 is in case they are large enough to trigger distant earthquakes away from the rings. It looks like you used quakes >5.5. You could try >5.0-that way we will have bigger numbers, so better statistics. Plus, it is possible that it is easier to trigger a M5 than a M6....

I think some of you recognize that this is important-that if quakes are being triggered at 101-102 deg, then who knows how weak an effect you need to trigger. Maybe Canie and Roger can team to look at magnetic storms.

Yes, I know Lowell did all this already. But, science works that everything needs to be checked and evaluated. Lowell has some simple graphs, but more often it is statistical analysis-I like seeing the simple graph first. I know little about statistics, but do know enough that if you did a cross-correlation with the FFA distances, you would get a (highly?) significant slightly shifted peak at 101-102 deg...
Chris