At the risk of adding doomsday fears to your upcoming holiday crisis, new evidence discussed at a meeting of geologists in San Francisco this week suggests that the giant pool of magma beneath Yellowstone National Park is 2.5 times larger than originally thought and holds enough power to destroy the entire country.

The new findings were discussed at the American Geophysical Union, where a team of scientists used a system of seismometers to measure the underground cavern beneath Wyoming's majestic vistas. According to their research, the cavern measures 55 miles by 20 miles wide and anywhere from 1 to 9 miles deep. At that size it likely contains between 48 and 153 cubic miles of molten rock. As University of Utah professor Bob Smith told the BBC, "We’ve been working there for a long time, and we’ve always thought it would be bigger... but this finding is astounding." As one Dr. Jamie Farrell explained, “To our knowledge there has been nothing mapped of that size before."

Even more alarming are the scientists' findings on when exactly this supervolcano could erupt. By studying the layers of rock in the national park, scientist believe the Yellowstone supervolcano has erupted at least three times in the past at a frequency of about one in every 700,000 years. The first occurred 2.1 million years ago, the second 1.3 million years ago and — here's the kicker — the most recent one occurred roughly 640,000 years ago. Meaning we could be due for a supervolcano eruption pretty much any day between now and the next 60,000 years.

While there's always a chance North Americans will find another way to destroy ourselves and our continent in the interim (or that the frequency estimate is bunk), the effect of a Yellowstone eruption would be catastrophic. Soil samples reveal that the last time she exploded, it covered the entire continent in ash, rivers of lava flowed for hundreds of miles and the smoke cloud was screwing with the planet's climate for hundreds of years.

Anyway, even if Yellowstone doesn't throw the country into some Cormac McCarthy-esque hellscape, several other researchers took a look at other volcanic eruptions on the same stretch of the continent that occurred between 8 million and 12.5 million years ago. What they found were fewer of these ancient volcanoes than originally expected, but that their devastating effects were much greater than originally believed. So, basically: Something's gonna blow sometime and you should probably call your mother more.


Note: an earlier version of this post quoted the volume of the underground cavern as 125 and 185 billion cubic miles. Per the BBC it contains somewhere between 200-600 cubic km of magma. Or 48-153 cubic miles.