i would say it was a combination of the constant M flares we had followed by the X
We were being bombarded with particles from the flares for days straight directly before the Japan quake
although quakes are not triggered by just solar events, we can see that solar event do come into play with these earthly events
The next large quake we have i will do my best to crunch and gather all available data i can come across so it can be gone through to find any connections