Worryingly for Yellowstone, Professor Mather points out that supervolcanoes seem to put out a greater proportion of their ejected material as pyroclastic flows. That means towns near the ...

Scientists calculate that the pillar of ash from the Yellowstone explosion rose some 100,000 feet, leaving a layer of debris across the West all the way to the Gulf of Mexico. Pyroclastic flows ...

According to a HowStuffWorks documentary on Yellowstone, while the volcano ... The devastation would not stop there, as lava flows and pyroclastic materials could cover an area stretching over ...

Mount Spurr has been showing signs of an eruption since last year, but scientists think one is even more imminent.