When a volcano event is triggered for me (regardless of where it actually pops up) I get an announcement and a picture, so it's pretty easy to tell if it's a new volcano or an existing one. I think I've only seen "such-and-such reports increased (or decreased) volcanic activity" for other players, so it's hard to tell if they're getting a lot of new volcanoes or just eruptions from existing ones. When I see three or four of those announcements in a single turn, it seems to me the event (whichever it is) is firing too frequently. But a lot of this is colored by my own frustration at the two I spent most of yesterday staring at. Naturally, no sooner had I complained above, than I loaded up my game and they both went to sleep.
The perverse thing is I actually like the first volcano that pops up. +1

in any tile my lonely capitol is going to use and fairly often a free Obsidian? Yes, please.