Supervolcano: Yellowstone's Hidden Magma Plumbing Revealed by Supercomputers

The Yellowstone supervolcano rises more than 9,000 feet above ground. Sculpted by 2 million years of explosive volcanic activity, the nation's first national park is hiding massive calderas—deep, cauldron-like craters—and a mantle plume.

Like an iceberg, there's far more to Yellowstone than the peaks and troughs we see above the surface. Vast, ancient and incredibly deep, scientists are only just beginning to crack the supervolcano's mysterious plumbing.

Now, researchers have used supercomputers to explain the strange but powerful network of structures hiding deep in the belly of the beast. Their research was published in Geophysical Research Letters.

4_17_Yellowstone Geyser
Steam rises from the Crested Pool hot spring in the Upper Geyser Basin of the Yellowstone National Park. The water that fuels Yellowstone's geysers and hot springs also cools hot magma rising to the crust below the park. Mark Ralston/AFP/Getty Images

Seismic data published in 2014 and 2015 suggested two big bodies of magma might be hiding in the Earth's crust—one just below the surface and one between 12 and 27 miles deep. The new computer modeling predicts a mostly solid layer of rock sits between these two magma bodies.

Related: Yellowstone's supervolcano may be fueled by 200-mile-wide plume of hot rock

Three to six miles below the surface, cold and rigid rocks yield to the hot and partially molten rocks below. This temperature transition captures rising magmas, which clump together in a sill, the research suggests. This enormous horizontal block of rock can stretch up to nine miles thick.

The modeling results match earlier seismic observations, study co-author Ilya Bindeman, a professor at the University of Oregon, explained in a statement.

4_17_Magma Sill Yellowstone
A graphic provides new structural information, based on supercomputer modeling, about the location of a mid-crustal sill separating bodies of magma Yellowstone. Dylan Colón

The upper magma body, researchers think, is mostly made up of rhyolitic magma. This sticky and gas-rich silica is behind incredibly violent explosions. Pressure slowly builds in this relatively cool magma that, every now and then, erupts in enormous explosions. "Our modeling helps to identify the geologic structure of where the rhyolitic material is located," Bindeman added.

Watch: World's largest geyser erupts at Yellowstone National Park

Although the research can't yet help scientists predict when supervolcanoes like Yellowstone might erupt, it can help explain past eruptions. An eruption 630,000 years ago was the last to form one of Yellowstone's four calderas.

Similar plumbing, lead author Dylan Colón, a University of Oregon doctoral student, added, could be hiding beneath the surface of supervolcanoes worldwide.