Thanks Tim, again very detailed information; I'll have to digest all that stellar wind info first.
I'm still trying to figure out why Io is the only moon with all these volcanoes. Saturn is very similar to Jupiter in size and distribution of it's satellites. Tidal flexing should also be working in some of Saturn's moons (Dione or Rhea perhaps) but since there's no volcanic activity on any of those moons, my guess is that other mechanisms should be considered. Are there any other possible mechanisms to your knowledge, and since we know that Io is smack in the middle of Jupiter's electromagnetic torus (Jupiter's magnetic fields are way stronger than Saturn's) wouldn't it be just possible that this torus is actively shaping Io's surface?
Cheers.