Yellowstone supervolcano has much more magma than previously thought – scientists

Yellowstone National Park’s supervolcano has substantially more magma reservoir beneath the caldera than scientists previously thought, according to new research.

In addition, the newly found lava flows at a shallow depth that 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 the melt and makes assumptions about the distribution of how the melt is distributed in the subsurface of the Yellowstone magma reservoir, Ross Maguire, assistant professor in the department of geology at the University of ‘Illinois Urbana-Champaign and author of the study, told ABC News.

“We found that the magma reservoir in Yellowstone’s crust is likely to contain more melt than previously thought,” Maguire said, adding that there is up to 20 percent melt at shallow depth.

Previous studies have suggested that the fraction of partial fusion was between 5% and 15%, Maguire said.

The Yellowstone magma reservoir is not so much “a big magma reservoir,” with accumulation all in one body, Maguire said, but more like a “snow cone,” in which there is a solid component and a liquid component, Kari. M. Cooper, professor and chair of the department of earth and planetary sciences at the University of California Davis, told ABC News.

The findings show there may be some relatively small-to-moderate-sized magma bodies beneath Yellowstone that could be mobilized and expelled, Cooper said. Yellowstone tends to get a lot of attention because of the potential for “catastrophic and explosive eruptions,” Maguire said, but that’s not the most common type of eruption in the park.

“They would be similar in size to what has happened in the very recent history of Yellowstone which has produced a series of lava flows that filled the most recent caldera after the most recent very large eruption,” he said.

Despite the new discovery, the research does not indicate an eruption will occur soon, scientists said. There are no signs of “increased volcanic disturbances” in Yellowstone, Maguire said.

“That really doesn’t change the hazard assessment at all, because we already knew that. We already knew that this was recent activity,” Cooper said. “We already knew that this was the most likely type of activity to happen next.”

However, a key issue in assessing the dangers of volcanic eruption is determining how much magma is below the surface and where, and continued monitoring of the subsurface is important to provide a clear picture if the situation begins to change dramatically, said the researchers

In addition, Yellowstone is thoroughly monitored by the U.S. Geological Survey and the Yellowstone Volcano Observatory, Cooper said.