There are also theories that it's HAARP (aka the HAARP WEAPON) that's causing the noises. Put on a foil hat and go take a look:
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I remember reading a book (O-Zone/Theroux) where - among other things - they were using old tires to make mountains and control the weather. Now conspiracy theorists are hinting that HAARP is doing 'weather warfare', causing the tsunami in Japan last year, earthquakes - including the big earthquake in Haiti, plus all the other strange weather happening anywhere lately.
Also that it's run by the illuminati, they're practicing mind control, got hold of Tesla's death ray, the New Wold Order is using it to get rid of most of the world's population....etc etc.
But back OT, that it's HAARP that's making these noises and causing earthquakes and other stuff right afterward. Go do a search for HAARP on youtube and you'll get lots of hits, for those of you who like that sort of thing.