[rbosque]

Good question.

[Smokin' Joe]

A friend and I tried to figure where a large series of whorls in the aurora was over the North American continent, and came up with a minimg area up in Manitoba.

I think near surface ore bodies have a distortion effect on the magnetic field. Other disturbances may apply, but without knowing anything about where the blue spiral is pointing, it is really tough to say.

Someone might have a really neat laser lightshow setup, too...