If you’re worried a supervolcano lying beneath Yellowstone National Park could erupt and plunge the planet into a volcanic winter, then you may need to hear this.
While a future eruption, a prospect widely reported over the last year, is possible, geologists say it’s incredibly unlikely. The odds that Yellowstone’s sleeping supervolcano will erupt within a century and cause massive devastation is one in 10,000, which is about as likely as a very large asteroid hitting Earth, according to Jacob Lowenstern, a research geologist at the U.S. Geological Survey (USGS).
“It’s not impossible to rule out, but it’s a remote possibility,” said Lowenstern, who used to run the Yellowstone Volcano Observatory, which monitors volcanic activity.
Supervolcanoes have the power to spew more than 1,000 cubic kilometers of debris and hot ash into the air when they erupt, which would have catastrophic consequences, including changes to global climate and agricultural devastation, according to the USGS. They get labeled supervolcanoes only after they’ve already erupted to that magnitude. There are between five and 10 active supervolcanoes in the world, Lowenstern said. The most recent supereruption happened about 27,000 years ago in New Zealand. Long before that, there were two supereruptions at Yellowstone — the first happened 2.1 million years ago and the second occurred 631,000 years ago, according to the USGS.
Many Americans grew concerned that a supereruption was looming after the New YorkTimes detailed a project from a research team at Arizona State University. The team researched the events leading up to the last large eruption at Yellowstone. They found changes in the supervolcano’s system known to help trigger supereruptions, like magma flow, can develop faster than previously thought, according to the Times. “It’s shocking how little time is required to take a volcanic system from being quiet and sitting there to the edge of an eruption,” Hannah Shamloo, an ASU graduate student who was part of the research team.
While media outlets frequently raise the specter of an apocalyptic supereruption from the Yellowstone caldera, and while the region has indeed produced massive Earth-altering events in the past, scientists remain convinced, based on the size and shape of the current magma chamber, that such an eruption, were it to happen again, would likely not occur in our lifetimes. The USGS considers the risk of a caldera-forming apocalypse at Yellowstone in the next couple of thousand years “exceedingly low”.
Many people mistakenly took that to mean Yellowstone’s supervolcano was overdue for a massive eruption. Christy Till, who was also part of the research team, later tweeted that the research team at no point suggested Yellowstone’s supervolcano was expected to erupt. “All signs of activity at Yellowstone are normal,” she wrote. “There are NO signs of the eruption as some media outlets reporting.”
Lowenstern agreed, dispelling the notion that there’s a cycle to supereruptions. He added that there is no way to tell exactly when or if it will even erupt, but any kind of eruption in the next 100 years is very unlikely.
Since the last supereruption at Yellowstone, there have been dozens of other eruptions at the national park that were minor. “There’s no requirement that it has to have another large eruption,” Lowenstern said.
Reassuringly, the Yellowstone region is constantly monitored for potential signs of trouble, as well. The Yellowstone Volcano Observatory, a collaboration between the University of Utah, the United States Geological Survey, and the National Park Service monitors real-time seismic activity, land deformation (from GPS and satellite measurements), and thermal changes or chemical signals from the gases being released (from surface detectors).