I read that Mt. Suribachi on Iwo Jima, a Japanese island that was in the news about 76 years ago is also at somewhat of a risk—and could set off a nasty tidal wave if it blows.
Any place along the rifts on the earths crust have volcanoes that are hazard.
But Yellowstone is on a hot spot. Not to say there are not such around the world, but few are as studied as Yellowstone.
Last I knew, they figured that there is not to much eruptable magma under there. It needs to be around a certain per cent to be considered a very high risk.
Take Tambora for example. That one blew several thousand feet off the top. Now that it happened, the next eruption many believe wont be much. Not so with the likes of the Long Valley Caldera. That one has a whole lot of magma under it and it. Way more than they thought before.
A caldera forms when several vents open up round the rim. They join up by cracks and after a lot of the magma is let out, the whole center collapses because the support is gone holding up the roof..so to speak.
Watch the movie Volcano..very accurate on how a super eruption happens.
I mentioned to watch the movie volcano.
NOT correct. Watch the movie SUPERvolcano.
My bad.