Yellowstone geyser erupted after years of dormancy. What does it mean for the volcano?

A geyser in Yellowstone National Park suddenly reawakened after years of sitting dormant — but there’s no reason to panic about an impending volcanic eruption, according to a new study.

“We don’t find any evidence that there is a big eruption coming,” Michael Manga, professor of earth and planetary sciences at the University of California, Berkeley and the study’s senior author, said in a news release. “I think that is an important takeaway.”

The popular national park sits on a supervolcano, and within the past 2 million years, volcanic eruptions have happened within the park, according to the National Park Service.

But it’s been about 174,000 years since the last eruption, the park service reported. Scientists have kept a close eye on the volcano’s activity, and they think it is extremely unlikely that an eruption will happen in the next “thousand of even 10,000 years.”

A 2018 eruption by the Steamboat Geyser — the tallest active geyser in the world — surprised some because it had been dormant for three and a half years, according to the news release, which was published by the American Association for the Advancement of Science’s EurekAlert.

“Some speculated that it was a harbinger of possible explosive volcanic eruptions within the surrounding geyser basin,” according to the news release. “These so-called hydrothermal explosions can hurl mud, sand and rocks into the air and release hot steam, endangering lives; such an explosion on White Island in New Zealand in December 2019 killed 22 people.”

The Steamboat Geyser can shoot water higher than 300 feet, according to the National Park Service.

In the study to be published this week in the Proceedings of the National Academy of Sciences, geoscientists at the UC Berkeley report that there were few indications that the volcano would blow soon. They found few indications of magma moving underground, which would be a prerequisite to an eruption, EurekAlert reported.

“Hydrothermal explosions — basically hot water exploding because it comes into contact with hot rock -- are one of the biggest hazards in Yellowstone,” Manga said in the news release. “The reason that they are problematic is that they are very hard to predict; it is not clear if there are any precursors that would allow you to provide warning.”

The ground near the Steamboat Geyser rose and shook some before the geyser reactivated, scientists found. The area around the Steamboat Geyser is also radiating more heat. But no other dormant geysers have reawakened, and groundwater has stayed the same temperature.

No one knows exactly why the Steamboat Geyser started erupting again in 2018.

The geyser is more variable than the popular and well-known Old Faithful Geyser, but Manga and his team couldn’t find evidence that new magma caused Steamboat’s reactivation.

“Internal plumbing” could have caused the geyser to become active again, and changes in the amount of silica rock buildup underneath the geyser could cause eruptions to halt, according to the news release.

“What we asked are very simple questions and it is a little bit embarrassing that we can’t answer them, because it means there are fundamental processes on Earth that we don’t quite understand,” Manga said. “One of the reasons we argue we need to study geysers is that if we can’t understand and explain how a geyser erupts, our hope for doing the same thing for magma is much lower.”

This story was originally published January 5, 2021 at 2:25 PM with the headline "Yellowstone geyser erupted after years of dormancy. What does it mean for the volcano?."