Na man.
Those erruptions are just because smokey uproots tres out of the ground.
It just seems that there is something more to it than that. Does anyone know what "ingredients" the teacher says to mix together? I believe she said water, but I'm not sure of what the other one is. Ben is manipulative & if he harnessed this "power" then he could use it as leverage against the "hostiles" since they have no clue as to what was being taught in their little secluded town. It seems that know one on the island knows what Smokey actually is, except Ben maybe.......

?
Firstly, I apologise for missing an "e" off trees.
Well they heard and felt the vibrations, then the hostiles invaded. So perhaps smokey is in cahoots with the original residents (Richard etc).
I can't bothered to look back over it but I thought the teacher told them that the other chemical in the mixture was bicarbonate of soda.