"Well, yellowstone erupts every 600,000 years or so. It's been 640,000 years since the last super eruption occurred if that tells you anything. there's not a set time when it's going to happen... maybe later tonight or in 1,000 years. it's impossible to tell... although scientist predict that there will be warning signs. Increase of activity (earthquakes) but probably with greater magnitude than we've seen recently... more cracks in the area... more gases... there's no doubt that scientists are monitering that area closely right now... but don't expect to see anything in the media about it. they know it would create a bunch of panic and it's quite likely that nothing's even going to happen in our lifetime anyways. but... it will erupt sometime."
http://answers.yahoo.com/question/in...4153405AAsUFiU