That's interesting. I don't recall hearing about a moon phase connection to large quakes, but it doesn't surprise me. Southern California lore has had some reliability connecting Santa Ana winds, sudden temperature changes, lost pets, pet behavior and insect behavior to impending earthquakes.
Excluding the stand-by mode of Mt. St. Helens, there's California, Turkey, Greece, Iran etc. On the USGS site, there was mention that Japan regularly has an earthquake every 5 minutes.