Yellowstone’s Tallest Geyser Keeps Erupting And No One Knows Why

Steamboat, the tallest geyser in the vast Yellowstone National Park, isn’t reliable at all, unlike the more famous Old Faithful that belches steam with regularity. But the fact is, Steamboat has been more faithful lately — spewing eight times since March 14, after being silent for nearly four years — and that puzzles scientists.

The latest eruption was Monday morning, when Steamboat shot boiling hot water hundreds of feet into the air. Steam billowed from the geyser for hours longer.

Steamboat is located in the Norris Geyser Basin, known to have the hottest and most changeable thermal area in nearly 3,500-square-mile wilderness park that sits on a volcanic hot spot. That accounts for the geyser’s towering columns of steam — it's very, very hot underground — but leaves some questions unanswered: Why now, and is it a sign the giant volcano is waking up?

Scientists aren't sure about the first question, but aren't too worried about the second one.

“It is a spectacular geyser,” Michael Poland, the U.S. Geological Survey’s scientist in charge of the Yellowstone Volcano Observatory, wrote CNN in an email. “When it erupts, it generally has very big eruptions.”

A string of eruptions isn’t unheard of, but it hasn’t happened at Steamboat in decades, and tourists are flocking to Wyoming to catch a glimpse of Steamboat before the geyser quiets for no one knows how many months or years. Until this recent series, the last eruption was in September 2014.

Data collected so far suggests a pattern to the eruptions within the series and if that proves out, the days surrounding June 11-12 are good dates to potentially see the Steamboat geyser erupt, Forbes reported.

"Most geysers erupt infrequently, unlike Old Faithful, so Steamboat is not enigmatic in that regard,” Poland told CNN. “But Steamboat has a mystique about it because it is the tallest active geyser in the world. It gets attention because of this, and rightly so.”

Scientists missed the first Steamboat eruption. The Norris Geyser Basin is close to tourists in early spring until the snow melts, and though scientists arrived in time to see steam, they missed the main event. They missed the second and third eruptions as well, including one on April 19 that occurred 15 minutes after a team of geologists staking out the geyser left for the day.

Scientists “were bummed," Poland told CNN, "especially because they didn’t realize that an eruption had occurred until after they had returned to the office (about an hour drive away). If they had just left a few minutes later, they might have seen the eruption in their rear-view window.”

Yellowstone is considered by some scientists to be a “supervolcano” capable of spewing more than 240 miles of magnum. Two of Yellowstone’s last three major eruptions met the criteria, but the last lava flow was about 70,000 years ago. The Yellowstone Caldera was created more than 640,000 years ago, and an eruption approximately 174,000 years ago created what is now the West Thumb of Yellowstone Lake.

The volcano is still active and hot. Earthquakes occur below ground at a rate of 1,000 to 3,000 a year, according to data collected by the University of Utah Seismograph Station, but scientists don’t expect the volcano to erupt in the next thousand years.

The Steamboat activity is "normal behavior" for geyesers, which "are supposed to erupt," Poland wrote in the email to CNN.

“The geysering is reflecting processes that are occurring in the shallowest part of the system — tens to perhaps a few hundreds of meters deep, whereas the magmatic system starts about 5 km down,” he wrote.

Jamie Farrell, a research assistant professor of seismology at the University of Utah and chief seismologist of the Yellowstone Volcano Observatory, told CNN in an email that activity in the caldera, which has been subsiding since late 2015, doesn’t seem related to the spate of Steamboat geyser eruptions.

What scientists are less sure of is whether there’s a new thermal disturbance or if the geyser is just entering a period of increased activity, which happens every now and again. In the 1980s, multiple eruptions were separated by weeks and, in some cases, days. 2003 was another active year for the Steamboat geyser.

“The current eruptions may simply reflect the randomness of geysers,” the U.S. Geological Survey pointed out. But it could be years before it happens again.

Scientists are placing more seismometers near Steamboat geyser and collect signals to see “if there is anything that relates to the ‘build up’ to an eruption,” Farrell wrote to CNN. “These can possibly give us a way to predict when the geyser will erupt but can also give us insights into what is happening in the subsurface plumbing system before an eruption.”

The USGS has been tweeting about the Steamboat geyser, and so have some people who have seen its showy eruptions.

Image: 2010 file photo by Michael Weber/imageBROKER/REX/Shutterstock