I noticed that a fellow who must be the Pat Robertson of Iran has declared that extra-marital sex is creating earthquakes. Now, even by the standards of Iran this seems pretty crazy. France is not wracked by earthquakes. This ought to be enough to scotch this theory in my view.
In fact, outside of California and Italy I can not think of one place that suffers from earthquakes, that is a place a neutral observer would consider higher on the adultery scale than the places that do suffer it.