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It started off well, but ends up being a hodge podge of catastrophic events with no one theory to tie in all the events. TBH when the character in the movie states that no one has a clue as to what's happening, I was in total agreement. I'm quite certain that not even the director bothered to analyse what could cause the events - he must have gone like - "earthquake - check, weird clouds - check, ash cloud - check, tsunami - check, fiery cloud - check; we'll decide what ties in all that in time for the sequel".