Everyone knows about Yellowstone Park, the oldest national park in the United States. But what people may not know is that it sits right on top of one of the biggest volcanoes on earth. And, contrary to initial assumptions about the volcano, it is alive. The most recent explosion was 640,000 years ago and was a thousand times the size of the Mt. St. Helens eruption in 1980. Apparently, the question about another eruption of Yellowstone isn’t if, but when.
Joel Achenbach, staff writer with the Washington Post and author of the National Geographic Magazine article "When Yellowstone Explodes," which appears in the August 2009 issue
Jacob Lowenstern, research geologist with USGS and the scientist-in-charge at the Yellowstone Volcano Observatory