World's Tallest Geyser Erupts For the First Time in Eight Years at Yellowstone

Everyone knows Old Faithful, the geyser so reliable 19th century explorers dubbed it "Eternity's Timepiece." Now meet Steamboat, Old Faithful's embarrassingly erratic brother that, after eight years of quietude, suddenly erupted 250 feet into the air for nearly 10 minutes on Wednesday.

Capable of reaching up to 300 to 400 feet, the world's tallest active gesyer has a tendency to either overwhelm its fans or, as has been the case of late, keep them waiting -- for years.

According to park officials, the last time the geyser put on a show was May 23, 2005, whereas in 1964 it erupted a record 29 times.

The most recent blast, which took place at 7:30 p.m., was witnessed by several dozen visitors lucky enough to have been in the area when it occurred, including freelance photographer Robb Long.

"It was an amazing experience. This thing sounded like a locomotive," Long told the Associated Press. "Everybody was frantic, taking pictures. People were running down there trying to get to it before it went away, and park rangers were running around trying to gather up people so they didn't get too close."

According to CNN, it took park rangers two hours to arrive on the scene, having been tipped off by the electronic heat sensors placed at each of Yellowstone's geysers.

"When it jumps up, we know we've had an eruption shoot up," Hottle said, explaining that in the case of Steamboat, "we saw that jump and then some folks called that it happened."

Geysers are a rare formation with more than half of the world's total calling Yellowstone home. They are defined as hot springs with constrictions in their plumbing that prevent water from circulating freely to the surface where heat would escape. According to the National Park Service, the deepest circulating water can exceed the boiling point in terms of temperature but are kept quiet by the overwhelming weight of overlying water. However, as the water rises, steam forms, expanding as it nears the top of the water column. And it's at this critical point when the confined bubbles actually lift the water above that the geyser begins to overflow, reducing pressure on the system and causing violent boiling to ensue. Tremendous amounts of steam is then finally free to escape, pushing water out of the vent with great force until the water reservoir is depleted or the system cools.