The giant volcano beneath Yellowstone National Park could explode sooner than expected, say scientists who are studying the site.
Analysis of minerals in the fossilized ash has shown that during previous eruptions, changes in temperature in the lead-up to the explosion occurred much faster than previously thought.
A powerful eruption occurred about 630 thousand years ago, shaking the region and creating the Yellowstone Caldera, a 65 km wide depression that covers most of the park.
The volcano is so large that a violent eruption can "choke" the Earth's atmosphere with ash.
Researchers from Arizona State University (USA) analyzed evidence of the eruption and believe that the supervolcano woke up after two streams of fresh magma poured into the reservoir below the pulpit.
Although a volcanic eruption can lead to dire consequences if it explodes, there is no need to worry for now. New data show that the temperature in the vicinity of the volcano rose in the decades before the eruption, and not in the centuries, as previously thought.
So what happens if the volcano explodes tomorrow? Depending on the scale of the eruption, the volcano can cover large parts of the United States with hazardous ash. The Earth's atmosphere will likely be filled with the same ash. Ashes in the atmosphere will cool the Earth, posing a threat to all life on the planet.