Well I just heard recently. And my boss told me they just found a huge volcanic chamber directly under the chamber they knew about and its a lot larger then the previously knew about and it feeding the previous one a lot faster then anticipated.
I pulled a quote I posted earlier regarding Yellowstone..
"if it's not from YVO regarding Yellowstone volcanic activity it's a rumor plain and simple or flat out lie"
http://doomsdayprepperforums.com/index.php?threads/nuclear-war-intel-here.5905/#post-70428