well there definitely is something magetic in there, as seen by jack's key, and all the stuff flying into it in the last episode...
i read a really cool theory and one part of it was that hanso was trying to bring peace to the world... his idea was to unite us against a common, non-sentient "foe"... create a natural disaster so great that it would force man together to survive, or such... but at the same time it would have minimal casualties... and the idea was to do something that would simultaneously destroy every electronic device on the planet... the theory dealt a lot with electromagnetism and triggering a polar shift, possibly as just a disguise so people thought it occurred naturally, or maybe as part of the effect...
the theory itself was refuted on other grounds, but those parts still stand
maybe pushing the button actually causes it to hold its charge, not release it... and when they didn't push it, the charge from however long was released in a big emp blast