There’s a volcano underneath Yellowstone. Actually, it’s a supervolcano. It’s erupted three times in the last two million years, the last time being 640,000 years ago, and all three eruptions produced enough ash to fill the Grand Canyon. It’s going to erupt again and send us back to the Stone Age. Okay, relax, sorry if I made you spit out your latte in panic. It’s not going to erupt anytime soon. In fact, according to vulcanologists (the people who study geologic eruptions, not Trekkies), “the yearly probability of another caldera-forming eruption could be calculated as 1 in 730,000 or 0.00014%. However, this number is based simply on averaging the two intervals between the three major past eruptions at Yellowstone — this is hardly enough to make a critical judgment. This probability is roughly similar to that of a large (1 kilometer) asteroid hitting the Earth.” But they add the decidedly less than comforting qualifier: “Catastrophic geologic events are neither regular nor predictable.”
So for no other reason that we can see except to scare the bejeezus out of us, scientists at the United States Geological Survey have modeled the devastation we could expect in the unlikely event of “a modern day Plinian supereruption.” 240 miles of ash would be spewed into the atmosphere to form a giant “umbrella cloud” of debris that would shut down communication and air travel, much like what happened just a few years ago--and again last week--after a volcano eruption in Iceland. It gets worse: water supplies and crops would be ruined; it would be hard to drive, and people would develop respiratory problems. And the climate itself would change significantly. While there are no historical examples large enough to draw a comparison, the researchers note that the considerably smaller Tambora eruption of 1815 “cooled the planet enough to produce the famed ‘year without a summer’ in 1816, during which snow fell in June in eastern North America and crop failures led to the worst famine of the 19th century.” But hey, relax, a massively devastating volcano eruption is probably not going to happen. Then again, don’t you think we’re overdue for one?