Brigham Young University geologists have found evidence of some of the largest volcanic eruptions in earth’s history in their own backyard. The scientific journal Geosphere has published some of their recent findings about supervolcanoes.
Looking at the land West of Cedar City, known as Wah Wah Springs, there is no indication that there was any kind of volcano, let alone one of the largest eruptions in earth’s history. But BYU geologist Myron Best says it’s been hidden in plain sight for millions of years.
“When I tell people that there was a huge supervolcano caldera 30 miles in diameter and maybe 3 miles deep on the state line, they look at me like I’m crazy,” Best says.
This was not the type of volcano that most of us think of - lava spewing out of a mountain. A supervolcano is an underground magma chamber capable of a massive explosion. Best says 30 million years ago, a plateau stretching across the Utah-Nevada border erupted, collapsing to form a large hole or caldera. Based on the deposits that have been found, it’s estimated to be about 5,000 times larger than the 1980 Mount St. Helens eruption.
“The explosive activity is so violent, it injects finer ash high into the atmosphere where it’s caught up by the jet stream, and that jet stream transported this fine ash at least as far as Nebraska and probably covered much the continental United States,” Best says.
Over a 30 year-period, Best and his BYU colleagues have worked with 600 students to piece together a geologic map of the supervolcanoes that occurred in this region so long ago. Best says there is no risk of eruption in this region today, but he says you can find an active supervolcano beneath Yellowstone National Park, and there is a real possibility of another eruption there sometime in the future.