Earthquakes, not volcano, biggest Yellowstone threat, says expert
July 18, 2019
POWELL — The world’s foremost expert on the Yellowstone caldera and the national park’s geophysical characteristics has a sense of humor.
“I want you to visit Yellowstone before it visits you,” Robert V. Smith quipped at a recent presentation in Cody.
Smith admits a volcanic eruption would be catastrophic, but he says it is far from the biggest natural danger in the park.
“I’m going to tell you right now, Yellowstone ain’t about to blow,” Smith said during his July 11 talk at the Buffalo Bill Center of the West.
About once or twice a week, Smith reads of impending disaster from tabloid-style media outlets, many in the United Kingdom.
“Don’t believe any of this unless you call me and verify it first,” he said.
Smith is a distinguished research professor and emeritus professor of geology and geophysics at the University of Utah and director of the University of Utah Seismograph and GPS Network in Yellowstone. He began his career studying the geothermal features in Yellowstone in 1956 and is in his 63rd year of research. He’s much more concerned about the danger to regional communities posed by earthquakes.
“They are killers,” he said.
Smith was on the ground researching the area when the last fatal earthquake hit the Greater Yellowstone Ecosystem. On Aug. 17, 1959, a 7.5 magnitude earthquake rocked Hebgen Lake, Montana, killing 28 people.
There are 30 seismograph stations inside Yellowstone recording thousands of earthquakes a year — most too small to notice. The monitoring system cost more than $10 million. The instruments are so sensitive they can measure the flushing of toilets at the Old Faithful Inn between eruptions of the namesake geyser.
If Yellowstone’s supervolcano does blow, Park County is unlikely to fare well. Smith said an eruption could last for days, weeks or even years, five to 10 times more powerful than the 1991 Pinatubo eruption in the Philippines that killed 700 — spewing enough material to fill the Grand Canyon twice and resulting in a volcanic winter, possibly for years, at temperatures of about 15 degrees Fahrenheit.
“They can last for decades,” Smith said.
Evidence of the last eruption, about 640,000 years ago, can be found across most of the U.S. One result of eruptions in Yellowstone was the loss of a large part of the Teton Mountain Range.
“It used to extend all the way up to the Gallatin Range [in Montana]. They were all blown away,” Smith said.
The Yellowstone caldera covers much of the park and has an active magma field below the surface, heating ground water and causing the beautiful geysers which made the park famous. If the ground does begin to shake and an eruption is imminent, it probably won’t help to panic.
Smith, an octogenarian, spent much of his time going down memory lane. His slideshow documented his adventures, which have resulted in about 200 scientific papers, hundreds of presentations at scientific meetings worldwide and far too many awards to mention.
While he spent decades researching Yellowstone, Smith said the dangers of park’s geology weren’t really appreciated until the 1990s. Then, in 2005, the British Broadcasting Corporation (BBC) released a documentary about what would happen if the Yellowstone caldera erupted. They called it a supervolcano for the first time.
“I kind of wanted it to be called the Yellowstone giant volcano, but globally it became known as the supervolcano,” Smith said.
The term captured the imagination of viewers and is still the subject of numerous articles from British tabloids warning about the inevitable catastrophe.
Smith’s book, “Windows Into the Earth: The Geologic Story of Yellowstone and Grand Teton National Parks,” is the most popular scientific work on the subject.