Millions of visitors each year travel to Yellowstone National Park to see the natural wonders that come from its iconic hydrothermal systems. For those sightseers looking in awe at an attraction such as Old Faithful, however, there’s never been a thorough, data-driven understanding of what’s taking place beneath the surface.
In an effort to better understand Yellowstone’s hydrothermal systems, scientists from the University of Wyoming, U.S. Geological Survey and Aarhus University in Denmark participated in a study using airborne technology to explore subsurface water flow.
Bill Gern, UW vice president for research and economic development, said uncovering the subsurface secrets in Yellowstone is exciting and important research.
“I think it’s really important for Wyoming to understand Yellowstone,” he said. “It is probably the most important tourist attraction in the world. More importantly, we don’t have a full understanding of how it operates. … (the) project that Dr. Holbrook ran was one where we could really start to fundamentally understand the under plumbing of Yellowstone and how it operates in a real way with major data.”
Steve Holbrook, a UW professor that participated in the project, presented a snapshot of those findings Monday to a full classroom in the S.H. Knight Geology Building.
He said the research is helping to answer questions that humans have been asking since they’ve seen features such as Old Faithful, Yellowstone’s famous geyser named so because of the frequency of its eruptions. Since Yellowstone became the world’s first national park in 1872, Old Faithful has erupted more than a million times.
“If you had a fieldtrip of eighth graders standing there on the boardwalk at Norris Geyser Basin, somebody in that group of kids is going to ask, ‘Where does that water come from? What’s underneath it? I can see a few feet down into this pool, where does it go?’” Holbrook said. “We’re answering those questions.”
Scientists employed a helicopter with SkyTEM survey system technology to provide a regional view of the earth’s crust beneath the surface in the world’s first national park. Hoping to distinguish the characteristics that comprise the hydrothermal systems, flights began in November and concluded in December.
“It’s going 80-100 kilometers an hour, which is much, much faster than we can work when we’re carrying stuff on our backs and laying on the ground,” Holbrook said.
The helicopter electromagnetic and magnetic, or HEM, survey was operated by the SkyTEM system.
SkyTEM is a Denmark-based geophysical surveying company. In a series of low-altitude flights on pre-planned grids, the survey focused on the Mammoth-Norris corridor, the Upper and Lower Geyser Basins and the northern end of Yellowstone Lake.
An electromagnetic system, which Holbrook said is basically a “loop of wire,” was suspended from the helicopter’s base, sensing and recording voltages that can be related to the ground’s electrical conductivity.
“This is going along and doing an electromagnetic sounding continuously,” Holbrook said. “That sounding takes a couple hundred milliseconds, so it’s always going. And then you can stack them together. We stacked them together and made individual soundings about every 20 meters along this line.”
Combined with existing data, scientists think they could close some major gaps between the surface water systems and deeper magmatic system.
So, what is going on beneath Old Faithful? Holbrook said data show the hydrothermal systems that are feeding the geyser. Though it remains speculative for now, he said he thinks there could be meteoric recharge taking place, where Old Faithful’s famous spurts of water are fed by precipitation.
Ultimately, Holbrook said the data are “big and unique,” and go a long way toward informing scientists about Yellowstone’s unique geology.
“Everybody wants to know what’s under there,” he said. “There’s a strong component of just people’s curiosity — this is the most famous hydrothermal system in the world. There’s everything from trying to make displays in museums based on reality to geologists and geochemists understanding the systems at that level. You make a measurement in a hydrothermal pool, and we can tell you how it’s connected to other pools or not in the subsurface that might explain the plumbing systems. It might explain where you’re seeing the effects of rainwater entering the systems and other areas where we’re not. And it might ultimately shed some light on all these strange, unique life forms.”
By filling a significant information gap, Holbrook said scientists now have a “plethora” of questions to tackle and years of science discovery ahead.
“We’re turning over new stones and are finding things we didn’t know we’d find,” he said. “We have to ask, ‘Now, what does that mean?’ These subsurface views of the hydrothermal systems in Yellowstone over large areas and down hundreds of meters are absolutely unique. This is a view of the underpinnings of these systems nobody has ever had before. So, it’s going to raise all kinds of new questions.”