The oldest, most famous national park in the United States sits squarely atop one of the biggest volcanoes on Earth. The Yellowstone supervolcano is very much alive and has the potential to blanket the US in a “nuclear winter.”
If the Yellowstone supervolcano were to erupt it would be one thousand times as powerful as the 1980 Mount St. Helens eruption, experts claim. The volcano at Yellowstone National Park in Wyoming and Montana sits atop a huge reserve of molten rock and last erupted 640,000 years ago. In April, scientists at the University of Utah discovered an enormous secondary chamber deeper beneath Yellowstone National Park that’s so large it is partly-molten rock could fill the Grand Canyon 11 times over.
Though it has been dormant for more than 70,000 years, scientists say that we can’t rule out the possibility that an eruption may some day take place.
If the volcano were to erupt, a mixture of magma, rocks, vapor, carbon dioxide and other gases would eventually push out from the ground, creating a dome shape with cracks. The dissolved gases would them explode, releasing the magma across the park.
The eruption, the say, could kill as many as 90,000 people almost instantly and release a 10 ft layer of molten ash 1,000 miles from the park. “The ash would block off all points of entry from the ground, and the spread of ash and gases into the atmosphere would stop most air travel, just as it did when a much smaller volcano erupted in Iceland in 2010,” HowStuffWorks reported. “Sulphuric gases released from the volcano would spring into the atmosphere and mix with the planet’s water vapor. The haze of gas that could drape the country wouldn’t just dim the sunlight — it also would cool temperatures.” These falling temperatures would damage our food supply, destroying crops and causing a worldwide food shortage.
An eruption at Yellowstone would create an “umbrella cloud” of ash which would expand evenly in all directions. “In essence, the eruption makes its own winds that can overcome the prevailing westerlies, which normally dominate weather patterns in the US,” said Larry Mastin. Larry Mastin works for the U.S. Geological Survey at the David A. Johnston Cascades Volcano Observatory where he specializes in the physics of explosive volcanic eruptions. Even these smaller levels of ash would be disastrous for the US. Ash from previous eruptions of the Yellowstone volcano has been found across the US on the east and west coasts. Areas covered in feet of ash would see buildings at risk of collapse and sewer and water lines blocked, and winds would form large dunes of ash that would cover roads and buildings. Highways across the country would become slippery and treacherous.
The USGS study says that electronic communication and air travel throughout the country would be shut down by an eruption. A huge cloud of ash thousands of miles across would also likely cause a year-long winter. The 1815 eruption of Mount Tambora in the Pacific produced an ash cloud tens of miles across that caused “a year without a summer” across the globe with snowfall in the North Eastern United States in June.
Though experts say that there is a one in 700,000 annual chance of a volcanic eruption at the site, there is still always the looming possibility. As the Huffington Post summed it up, “The bulging pocket of magma swishing around beneath Old Faithful might never blow its lid again. Or, it might put on a surprise fireworks show next Independence Day. Scientists just don’t know.”