A surprise eruption in Yellowstone National Park shot steam, water and dark-colored rock and dirt high into the sky Tuesday and sent sightseers running for safety, the reports. The hydrothermal explosion happened around 10am in Biscuit Basin, a collection of hot springs a couple miles north of the famous Old Faithful Geyser. Video posted online showed a couple dozen people watching from a boardwalk as the eruption sprayed and grew in front of them.
As water and debris began to fall, they ran to keep clear, some yelling "Back up!" and "Holy cow!" People then turned to watch the spectacle under a huge cloud of steam. A hydrothermal explosion happens when water suddenly flashes to steam underground. Such blasts are relatively common in Yellowstone.
No injuries were reported, but the Biscuit Basin area was closed for visitor safety. The eruption damaged a boardwalk that keeps people off Yellowstone's fragile and often dangerous geothermal areas. "We saw more steam coming up and within seconds it became this huge thing," says one woman who was on a tour at the time.
"It just exploded and became like a black cloud that covered the sun." An expert estimates the explosion sent material about 100 feet into the air. Rocks that fell from the sky smashed the boardwalk they had been walking on.
March's mom, who had been sitting on a bench near the explosion, was shaken and dirty but otherwise fine, she said. The explosion could have resulted from a clogged passageway in the extensive natu.