Cross-posted from Geotripper
Is Yellowstone gonna blow? Sure. Will everybody die? Sure, absolutely. But there is pretty much no connection between the first question and the second. Yellowstone caldera will in fact erupt again some day; it's a forty mile wide caldera with a huge magma chamber miles deep in the crust. That's the reason there are geysers there, and all those hot springs. And everyone will die, eventually. That's kind of a rule about living. But worrying about whether I'm gonna die from an eruption at Yellowstone is so far down my list of concerns that I am more worried about being gnawed to death by a pack of angry prairie dogs. It could happen, but it is highly unlikely.
I'm writing on the subject because a commenter on my blog at Geotripper asked for my take on the news this week about the activity around the Yellowstone caldera (for the record, "supervolcano" isn't a geological term) and the possibility of a catastrophic explosion at the park. My best advice, before I finish with my own two cent's worth, is to check out the Eruptions blog here and here. Erik Klemetti does some excellent analysis of the story and how quickly things can be overblown by a media that thrives almost exclusively on spectacle, and has little use for reasoned discussions of the actual risks.
As I considered the question of an 'informed' response, I had to wonder if I'm not guilty of the same sort of exaggeration and sensationalism of cable news and other media. In my pursuit of educating others, I am not above discussing lurid tales of death and geological mayhem. After all, when I talk about volcanoes in class, I lead with Krakatoa, Tambora and Pompei, and I discuss the potential effects of a gigantic rhyolite caldera eruption such as those that took place at Yellowstone three times in the last two million years (not to mention broadly equivalent eruptions at Valles Caldera and Long Valley Caldera). I have a clear conscience on the matter, because I follow up with a discussion of the actual risk and probability of such events happening to our time; an eruption like the Yellowstone Caldera happens somewhere in the world every few hundred thousand years. Smaller, but certainly dangerous eruptions like those of Tambora (1815), Krakatoa (1883) and Katmai (1912) happen somewhere in the world on a scale of decades. And when these events take place there are clear signals that something is about to happen.
So, the Yellowstone Caldera floor rose around a foot during the last decade. There was an intrusion, a sill, that was filling and inflating with magma. There is nothing unusual or particularly alarming about this, as Yellowstone is an active magma chamber, and such events are normal. Although it has been 70,000 years since the last eruption in the park (and more than 600,000 years since the so-called 'supervolcano' eruption), it could happen again, but any activity would be accompanied by many other phenomena that would provide plenty of information about the scale of the eruption and the hazard to people in the region. My take? Learn about Yellowstone; it is a fascinating place, worthy of our attention and worthy of protection as a crown jewel in our national park system. But worry about the end of civilization as we know it in a vast explosion of fire and volcanic ash? No, there are other problems that we need to think about.
The best quote on the matter? From Max Read at Gawker: "But who do you trust, some kind of "professor," or your overactive imagination?" To which I might add: "But what about professors with overactive imaginations?"