It's hardly unscientific either really.... The moon being at its peak potential for gravitational influence could easily influence seismic activity, it would only be a fool who would say otherwise.
Whether or not the Supermoon theory will be as catastrophic as the loonies are saying will have to remain to be seen. But the fact is that the moon will be exceptionally close and potent in the upcoming days and weeks and that the entire Ring of Fire should take heed of that. Japan is in a highly volatile region, but an 8.9 quake corresponding with the moon's activities seems pretty obviously connected to me.
It was strange we got a Tsunami warning on the radio, kind of eerie! But I live on the Inside Passage, so I am more or less safe from Tsunamis.
My heart goes out to Japan and I say good luck to all those on the Pacific outer coast!