The Moon Io- y is there volcanic activity?? and what is diff about its appearance?

it's io's orbit around jupiter, ti's not a perfect circle, as it moves closer and father away from jupiter along it's orbit, jupiter's mive gravitational pull contracts and warps the moon, which in turn creates heat, and lots of it... io is thought to have alot more heat and activity in it's core then earth... because jupiter's gravity also works at 'pulling' on the magma at the center, the eruptions are huge, and severely violent....