Lurking deep below the surface in California and Wyoming are two hibernating volcanoes of almost unimaginable fury. Were they to go critical, they would blanket the western U.S. with many centimeters of ash in a matter of hours. Between them, they have done so at least four times in the past two million years. Similar supervolcanoes smolder underneath Indonesia and New Zealand. |
RING OF FIRE: Mountain-size vents exploding
around the outer edge of an active supervolcano
smother the landscape in clouds of hot gas and ash.