A collaborative research effort between Chinese and American scientists has shed new light on the formation and evolution of supervolcano magma systems, offering insights that may enhance eruption forecasting and disaster preparedness. The study, published in the journal Science, focuses on the Yellowstone caldera, a prominent supervolcano located in Yellowstone National Park, Wyoming.

Supervolcanoes are capable of erupting enormous volumes of material—exceeding 1,000 cubic kilometers—potentially causing extensive environmental, climatic, and societal impacts. Yellowstone itself has experienced two major eruptions in the past 2.1 million years, ejecting approximately 2,500 and 1,000 cubic kilometers of volcanic debris in those events. Its well-documented geological and geophysical features have made it a key subject in volcanic research.

Traditional models posited that supervolcano eruptions are driven by large, vertically oriented pools of fully molten magma beneath the Earth’s crust. These magma chambers were thought to accumulate pressure over time until fracturing surrounding rock to initiate an eruption, fueled by a deep mantle plume rising from great depths. However, more recent studies have challenged this view, suggesting that instead of mostly liquid magma, these systems consist largely of a “mush” — a mixture of partially molten rock and solid crystals — which may endure for extended periods without erupting.

The new study advances understanding by constructing a three-dimensional model based on an integration of geological, geophysical, and geochemical data across western North America. The researchers found that magma beneath Yellowstone originates near the base of the North American lithosphere, roughly 100 kilometers below the surface. There, hot, partially molten rock slowly moves eastward through a narrow channel beneath the supervolcano.

The study proposes that this mantle flow is elongated and tilted rather than vertical, shaped by the dynamic interactions between the eastward mantle movement and the westward motion of the North American continent. This push-and-pull interaction appears to stretch and weaken the base of the lithosphere, creating a diagonal pathway enabling magma to ascend toward the surface. This mechanism accounts for the distinctive tilted shape observed in seismic data beneath Yellowstone.

“We provide the first comprehensive explanation of how magmatic systems beneath supervolcanoes form and evolve,” said Liu Lijun, the study’s corresponding author and a researcher at the Chinese Academy of Sciences’ Institute of Geology and Geophysics.

The lead author, postdoctoral researcher Cao Zebin, noted that the findings may have broader implications, potentially explaining magma system dynamics at other major volcanic regions, including the Toba supervolcano in Southeast Asia and the Altiplano-Puna volcanic complex in South America.

Liu emphasized that the model could eventually support improved forecasting of volcanic activity, akin to meteorological predictions, thereby enhancing early warning systems and reducing risks associated with future supervolcanic eruptions.