Tourists flock to see this geyser blow its top – launching superheated water vapor up to 185 feet (56 m) high – every 92 minutes in Yellowstone National Park, Wyoming, U.S.A. Geysers are rare geological features, and Old Faithful is doubly rare for its regularity. Researchers were baffled by the punctuality of its eruption until recently, when they managed to chart its subterranean plumbing. It turns out that a large chamber beneath Old Faithful fills with steam bubbles boiled by the molten magma below. Those bubbles become trapped in a tube that leads to the geyser’s mouth. The tube gradually fills with water, the pressure builds, and – whoosh – Old Faithful erupts right on schedule.
Picture Credit : Google