Experts study Steamboat geyser after series of eruptions.
YELLOWSTONE N.P., WYO. - Call it Yellowstone's unfaithful geyser.
Steamboat geyser has erupted five times since May 2000, shooting scalding water and rock as high as 300 feet into the air, and roaring 24 hours afterward. But Steamboat has not always been that dynamic; before the recent events, it had not erupted since 1991, and it has gone 50 years between known eruptions.
Although park officials are unsure of what is happening at Steamboat, they note that the region around the Norris basin has risen about five inches in the past few years, and that water temperatures there increased before an April 2002 eruption. Water flows have increased as well, possibly exerting pressure on Steamboat, and steam vents and springs have multiplied. These and some other shifts to the Norris basin's underground plumbing help to explain why Steamboat seems to have awakened.
Further complicating matters is that park officials are not sure that Steamboat is, in fact, becoming more active. They wonder if scientists are just keeping a closer eye on it.
"That's the million-dollar question," said park geologist Hank Heasler. "It has been more active than anyone has noticed before, but is that just because we're looking now - or because something is abnormal? We are not sure, but we can see things better than ever."
Among the ways the park keeps tabs on Steamboat is the monitoring equipment recently installed in the basin, which tests water flow levels, temperature, and even the smallest movements of earth. Satellite imaging and climate data will extract more clues, along with global positioning receivers and seismographs. The equipment will give scientists hard facts about the geyser's activity, so that they can rely on more than just eyewitness accounts of eruptions.
"We're getting an internal x-ray of the geyser basin that we have never had here before," said Heasler. "This is an effort to help scientists understand what's going on, but it will also help [the Park Service] understand the region and ensure its health and visitor safety."
The monitoring is providing more and better data of the geyser than the park has ever had, said Heasler, but it could be years before it produces scientific answers.
"Let's say the story of the Norris basin is a seven-volume Harry Potter series," said Heasler. "We're probably getting into the first paragraph of the first book. We're finding some fascinating things, and along the way, we'll get some important answers. But right now we're in the creative, not scientific, stage."
Earthly fireworks are nothing new in the Norris basin, where scientists have recorded yearly disturbances for decades. The difference of late, said Heasler, is that disturbances are happening in areas of high visitor foot traffic. That became a problem recently when scalding water and steam emissions caused the closure in the back of the Norris basin.
"We felt it was unsafe for visitors to walk on the trails there," said Heasler. "We are looking at moving some of the trail system and building more boardwalks, so that we can reopen the area."
Although eruptions in March and April of this year had no witnesses, park staff vividly recall eyewitness reports from a May 2000 eruption. Two people saw the geyser blow its top and scampered away, said Heasler.
"They gave us some very colorful descriptions of what it was like," he said. "They said the ground was shaking and rumbling, and water was flowing into the parking lot. They didn't know if that was normal, or if something pretty big was about to happen in Yellowstone."
