WangChung your underlying proposition that man can have no effect on the natural world is totally false. Just have a look around yourself and wake up.
I am not saying that we have had any impact on the frequency of earthquakes at all, but what is happening is alarming.
I do see the potential for the impact of the gravitational effect of the moon. If you saw the solar system doco recently you would realise that the ordering of Saturn's rings is due to the complex gravitational forces between all of Saturn's moons. If our own moon can cause strong tides then there is no reason the believe it cannot have a similar destabilising effect on the crust of the earth.
Plus we all know Japan is right on the edge of a fault line.
