How is "Thor" different from "Vulcan" in mythology?

Thor's hammer creates lightning in the sky, and Vulcan's lava from the earth. Nature is different in Northern Europe and the Mediteranean, so the natures of these two gods will be vastly different. Thor is from Northern Europe (norse), and Vulcan is from the Mediteranean. (what today is called Italy) I do not think they were connected to planets. To call both groups "pagan" is an oversimplification, as there was little in common in Pagan Northern Europe and Pagan Rome.