After reading THE GRINDING entry and hearing that it was based on real events, I had to know more.
We were looking for sounds that would be a good addition for the post and there were MANY, MANY links to events like this. It really gave me the creeps.
It seems like it's a very common thing all over the globe.
I've read everything from Haarp to thunder bouncing in the atmosphere to earthquake reverb to UFOs. Very wild stuff...and something I don't really care to experience myself! :)