Scientists working in and around Yellowstone National Park say that the supervolcano sitting under the tourist attraction may blow sooner than thought, an eruption that could wipe out life on the planet.
According to National Geographic, the researchers, from Arizona State University, analyzed minerals in fossilized ash from the most recent mega-eruption and found changes in temperature and composition that had only taken a few decades. Until now, the magazine reported, geologists had thought it would take centuries for the supervolcano to make the transition.
The discovery, which was presented at a recent volcanology conference, comes on top of a 2011 study that found that ground above the magma reservoir in Yellowstone had bulged by about 10 inches in seven years.
"It's an extraordinary uplift, because it covers such a large area and the rates are so high," the University of Utah's Bob Smith, an expert in Yellowstone volcanism, told the magazine at the time.
Features of the park, such as the Old Faithful geyser and the Grand Prismatic Spring that attract visitors from around the world, are signs of a huge magma reservoir rumbling below.
About 630,000 years ago, National Geographic reported, a powerful eruption shook the region and created the Yellowstone caldera, a bowl 40 miles wide that forms much of the park.
Perhaps ominously, according the ZME Science website, the previous eruption occurred in about the same timeframe before that — 1.3 million years ago — meaning that the system might be ready for another explosion.
The researchers, The New York Times reported, have determined that the supervolcano has the ability to spew more than 1,000 cubic kilometers of rock and ash — 2,500 times more material than erupted from Mount St. Helens in 1980 — an event that could blanket most of the United States in ash and possibly plunge the Earth into a volcanic winter.
The theory of a much shorter timeline than expected was developed by Hannah Shamloo, a graduate student at Arizona State, and several colleagues who spent weeks at Yellowstone’s Lava Creek Tuff — a fossilized ash deposit from its last supereruption.
According to The Times, Shamloo later analyzed crystals from the team’s dig that recorded changes in temperature, pressure and water content beneath the volcano — much like a set of tree rings.
“We expected that there might be processes happening over thousands of years preceding the eruption,” Christy Till, a geologist at Arizona State who is Shamloo’s dissertation adviser, told the paper. Instead, the crystals revealed an increase in temperature and a change in composition that had happened more quickly.
The pair also presented an earlier version of their study at a 2016 meeting of the American Geophysical Union.
“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,” Shamloo told The Times, cautioning that more research is necessary before definite conclusions can be drawn.