Boyko, since you posted on the thread that I started, I have to reply. Your post does not make sense to me. This could in part be your wording, meaning your English, or maybe your logic. Plate Tectonics provides the forces and stresses that make quakes in California. For intraplate quakes, far from a plate boundary, it is a little more complicated. John Vidale and Roger Hunter have done scientific studies as have others and it is well understood where and when the ocean and earth tides can enhance or suppress quakes: the effect is weak and only observable in certain situations. I say well understood; actually, those area that do show relations to tides probably need more study because it may shed some light on quake triggering in general: what the physical mechanism is.
Chris