Violent, scalding geysers and awe-inspiring wildlife draw thousands of visitors to Yellowstone National Park every year, but many tourists don’t know that the oldest national park, established in 1872, is located on top of the largest active supervolcano in the world.
Robert Smith, research professor of geology and geophysics, said in a lecture on March 18 at the Skaggs Biology Building auditorium that the Yellowstone caldera has been rising and falling for hundreds of years, but in the past four years the caldera, the crater-like impression from a volcanic explosion, has risen three times faster than the historic rate.
“This is happening today. It’s still going on,” Smith said. “Now, we aren’t predicting any imminent threat of eruptions, but it’s an active, dynamic system.”
The most recent super volcanic eruption in Yellowstone occurred about 640,000 years ago when a column of hot magma and molten rock worked its way upward, forming a magma chamber six to 20 miles below Yellowstone. The pressure of the chamber raised the land above it and after the explosion, the land collapsed into the empty chamber, creating a caldera, Smith said.
Smith has been studying Yellowstone for years and serves as coordinating scientist for the Yellowstone Volcano Observatory, supervising the operation of networks that monitor earthquakes and ground movements in the park and surrounding areas. He said they work with several other schools, including Harvard University and the University of Oregon, in studying the park.
Smith said visitors to the park will always drive uphill because the hotspot underneath Yellowstone is about 1,000 feet higher than any surrounding region.
He said the hotspot is responsible for three super volcanic eruptions during the past 2 million years. Frequent earthquakes, which used to occur about 2,000 to 3,000 times each year, kept the ground broken enough for pressure to be released.
“Geysers need earthquakes in Yellowstone,” said Smith, who has been at the U for 41 years and knows within seconds when an earthquake has occurred in the park.
There are 31 seismographs spread throughout the park that record and transmit data by radio waves, satellite waves, microwaves and wireless signals to the U in real time.
Smith ended his lecture by saying, “Visit Yellowstone, before it visits you.”
Ruthann Shurtleff, a geoscience major, said she is captivated with Yellowstone even though she has never been there.
“People think of something as stationary and it doesn’t change, like the earth doesn’t change, and that’s really not the case, stuff is always changing,” Shurtleff said.
Becky Gage, an earth science and teaching major, attended the lecture to learn more about Yellowstone, and said she has also always been fascinated by the park.
“I’ve been there three times, personally,” she said.
Smith said he often works with graduate students, many of whom have written theses on the earthquakes and volcanoes in the national park.
“We do everything that a normal scientist would do in a building, (but) we do it in the outdoors,” Smith said.
Clarification: In this article it says the earthquakes used to occur 2,000 to 3,000 times each year. They still occur but only a dozen are felt.