And Yellowstone's eruption could happen with less warning than previously thought.
Credit: Ignacio Palacios/Getty Images

A supervolcano on the caldera in northwest Wyoming in Yellowstone National Park could erupt sooner and with less warning than previously thought, according to a new study from the University of Arizona.

The supervolcano, which last erupted more than 600,000 years ago, could spew ash across most of the continental U.S., sending Earth into a volcanic winter.

According to The New York Times, an eruption at Yellowstone could send more than 1,000 cubic kilometers of rock and ash flying at once. “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,” study co-author Hannah Shamloo told The New York Times.

Researchers tested minerals in the fossilized ash and discovered that the last time the volcano woke up, fresh influxes of magma flowed into the reservoir decades prior to its eruption, National Geographic reported. Scientists previously thought that the composition change needed to trigger those magma flows took several centuries or even millennium. With the timeline shortened, humans would have far less time to prepare in the case of an eruption.

Yellowstone's volcano is closely monitored, however, and Michael Poland, the scientist-in-charge of the Yellowstone Volcano Observatory for the U.S. Geological Survey, told National Geographic that the supervolcano does not pose an immediate threat.

“We see interesting things all the time ... but we haven't seen anything that would lead us to believe that the sort of magmatic event described by the researchers is happening,” he said.