Thanks, John. Though I know of the work done on quake/tide correlation (mostly yours, I think), I actually find it kind of surprising that there is any correlation at all. As you imply, the speed of tidal changes pretty much rules out any likelihood of pore-pressure changes being causal, but that does not leave just loading! The gravitational component of tidal changes remains a possible factor, and one that, it seems to me, is a more likely one than loading.

Thanks for the remainder of your post, too. But left unanswered is my (implied) question of whether or not actual weight of rainfall, even unusually large amounts, could conceivably be a factor in precipitating (no pun intended) earthquakes. It seems, to me, that even the many meters of water in reservoirs would be hard put to constitute any significant increase in load in comparison to the many kilometers of rock overlying source zones.

Mike W.