YELLOWSTONE NATIONAL PARK -- In the last couple years, Peter Cervelli, who monitors the Yellowstone volcano, saw a major eruption of the world's largest geyser, an uplift of the Norris Geyser Basin and the largest earthquake in the park in 30 years.
While those were all noteworthy events, they're not indications that the Yellowstone super volcano is about to erupt, said Cervelli, associate director for science and technology at the USGS Volcano Science Center in Menlo Park, Calif. But that hasn't stopped the general public from speculating.
Cervelli has spent his career researching geophysics and monitoring volcanoes, first in Hawaii, then Alaska and now based in California, studying Yellowstone. During that time, one of the major changes he's seen, in addition to the changes in technology and monitoring systems, has been the way information, or misinformation, travels.
"There's sort of a disconnect between the way we scientists see things and the way some of the public sees it," he said.
The USGS Volcano Science Center gets an average of five emails a week from members of the general public who are worried about a Yellowstone eruption, he said. He also sees bad information travel on social media.
After the 4.8-magnitude earthquake in late March, the largest in 30 years, a video went viral of bison running down a road inside the park. The story that somehow got attached to the video was that the bison were running out of the park, fleeing the impending eruption they could somehow sense. In reality, the bison were running into the park.
Bison are a common sight in the park and often can be seen running, Al Nash, spokesman for Yellowstone National Park, said at the time.
That didn't stop the video from getting 500,000 views.
While the video got a lot of attention, the scientific story behind that earthquake is even more interesting.
Starting in late summer 2013, scientists started noticing that the Norris Geyser basin was rising. By November, the uplift began to pick up speed.
Over five months, the area rose 6 to 7 centimeters and moved southeast.
"It's not an extreme uplift rate," Cervelli said. "For Yellowstone it was at the high end of normal."
Then on March 30, the 4.8 earthquake occurred, and suddenly the uplift at Norris stopped. Then the area started to sink, and before long, everything was back where it started.
Scientists think gases deep below the earth's surface rose up through the crust and then met an impenetrable barrier and couldn't go anywhere. Pressure started to build and lead to a deformation on the earth's surface.
"The earthquake essentially let off the steam," Cervelli said.
The earthquake likely created a fracture that allowed the pressurized gases to be released.
"In an ideal world we probably could have seen them or detected them," Cervelli said.
However, the park is a big place and the USGS doesn't have gas monitoring equipment to cover all of it.
"We do have a lot of instruments but we also have a lot of park," he said.
Around the time the uplift began at Norris, Steamboat Geyser, the tallest geyser in the world, erupted. That geyser, located in the Norris Geyser Basin, doesn't go off very frequently or consistently.
"At the time I was pretty excited about this," Cervelli said.
He was hoping the geyser eruption and the uplift were linked and would help scientists better understand the dynamics of the geyser basin.
"It turns out that probably was a coincidence," he said.
However, he hopes he and his colleagues still can learn more from the uplift event. Uplift is fairly common in the park but typically occurs inside the caldera, which Cervelli said formed 640,000 years ago. Norris sits outside the caldera. Uplift also usually occurs over a longer timeframe and affects a bigger area, unlike the Norris uplift.
"It was short, intense and located at Norris," Cervelli said.
And it may help scientists better understand the interplay between the caldera and Norris.
What scientists already know is episodes of ground deformation are common and do not imply that an eruption is pending.
It's extremely unlikely that a super eruption of the Yellowstone volcano will occur in this lifetime. In fact, if you want something to worry about, Cervelli suggests worrying about a major meteor hitting the Earth. Statistically, that happens far more often than a Yellowstone super eruption.
Reach Tribune staff writer Erin Madison at 406-791-1466 or firstname.lastname@example.org. Follow her on Twitter @GFTrib_EMadison.