I wouldn't put any stock in that theory at all. I can't remember precisely where I heard that posited, hence the statement that it's not solid science (because it isn't). Further research in the New Scientist archives throws up a letter which suggests that a drop in pressure associated with a depression could be a trigger for volcanic eruptions (and hence, I suppose, earthquakes as the two are related), but a rebuttal of that letter says that rainfall would be more likely. So it could just be that I'm getting my geological processes mixed up. Or that I read something elsewhere. I'm sorry, that's not much use is it? Either which way, the point is that trying to tie real science in with the plot of a film is prone to failure. I think I just proved that point rather well by my own failure to research one statement thoroughly. (I think I just has my ass factchecked. Bargain.)