Thread:Thailog/@comment-1629132-20130203213802/@comment-4928331-20130204230036

Wind is just a form of kinetic energy, of air in motion. So yes, since rock is incompressible, it can be shattered by kinetic energy.

I suppose it is a toss up between wind or sound. I personally think it is sound, but I also think she's a homage to Samurai, who uses wind.