Yellowstone supervolcano has much more magma than previously thought: scientists
The supervolcano in Yellowstone National Park has significantly more magma reservoir beneath the caldera than scientists previously thought, according to new research.
In addition, newly discovered lava flows at shallow depths that have fueled previous eruptions, according to a paper published Thursday in Science.
The researchers mapped the speed of seismic waves beneath the Yellowstone volcano using a technique called seismic tomography. This 3D modeling of seismic waveforms measures the volume of melt and makes predictions about the distribution of how the melt spreads in the subsurface layers of the Yellowstone magma reservoir, Ross Maguire, assistant professor in the Department of Geology at the University of Illinois at Urbana-Champaign and author of the study, told ABC News.
“We found that the Yellowstone crustal magma reservoir is likely to contain more melt than previously thought,” Maguire said, adding that there is up to 20% melt at shallow depths.
Previous studies have suggested that the fraction of melting is between 5 percent and 15 percent, Maguire said.
Yellowstone’s magma reservoir is not so much a “big magma reservoir” with accumulation in one body, Maguire said, but more like a “snow cone” in which there is a solid component and a liquid component, Carrie M. Cooper, professor and chair in UC Davis’ Department of Earth and Planetary Sciences, told ABC News.
The findings indicate that there may be some relatively small to moderate magma bodies that are under Yellowstone that could be mobilized and ejected, Cooper said. Yellowstone tends to get a lot of attention because of the potential for “catastrophic, explosive eruptions,” Maguire said, but it’s not the most common type of eruption in the park.
“They would be similar in size to what happened in the very recent history of Yellowstone, which produced a series of lava flows that filled the most recent caldera after the last really big eruption,” she said.
Despite the new discovery, the study does not indicate that an eruption will occur soon, the scientists said. There are no signs of “increased volcanic activity” in Yellowstone, Maguire said.
“It really doesn’t change the hazard assessment at all because we already knew that. We already knew that was the recent activity,” Cooper said. “We already knew this was the most likely type of activity to happen next.”
However, a key issue in assessing the dangers of a volcanic eruption is how much magma is below the surface and where, and continuous monitoring of the subsurface is important to provide a clear picture if the situation begins to change dramatically, the researchers said. .
In addition, Yellowstone is closely monitored by the U.S. Geological Survey and the Yellowstone Volcano Observatory, Cooper said.