Scientists recently announced that Yellowstone National Park is rather gassy
A study in Nature magazine reported that Yellowstone is releasing a about 60 tons of helium from underground stores each year, an amount hundreds, possibly thousands, of times more than expected. Researchers with the U.S. Geological Survey estimate that enough helium comes up to fill one Goodyear blimp every week.
"We had sort of an 'Aha' moment where we realized, wow, that there's a lot of crustal helium coming out of Yellowstone — far more than we would have predicted," lead study author Jacob Lowenstern, a research geologist and scientist-in-charge of the Yellowstone Volcano Observatory, told National Public Radio.
When uranium and thorium decay, they produce helium, or in this case the isotope helium-4 (named for its two protons and two neutrons). Currently, the gas is gurgling up from a store that’s been trapped in the Earth’s core for up to 2 billion years. Scientists believe that the helium began its exodus up from the depths roughly 2 million years ago.
"That (2 million years) might seem like a really, really long time to people, but in the geologic time scale, the volcanism is a recent phenomenon," study coauthor Bill Evans, a research chemist at the USGS office in Menlo Park, Calif., told the LA Times.
The helium was initially released when a “hotspot” of collected magma fought its way to the Earth’s surface and caused a series of volcanic eruptions, the most recent of which occurred 640,000 years ago.
"Think of it this way: You have these old crustal rocks just sitting around for hundreds of millions, perhaps billions of years," Evans said. "They have this boring little existence, and then suddenly somebody puts the heat on under them and they start giving up all their long-held secrets."
Don’t worry though
This doesn’t mean Yellowstone’s supervolcano is any closer to erupting.
“"This really isn't a volcano story," Lowenstern said. "But it reveals how the Earth's crust behaves on a long time frame. The crust 'holds its breath' for long periods of time, and then releases it during tectonically and volcanically active bursts."