New Cornell University led-research challenges the long-standing belief that active volcanoes have large magma bodies that are expelled during eruptions and then dissipate over time as the volcanoes become dormant.

Researchers used seismic waves to identify magma chambers beneath the surface of six volcanoes of various sizes and dormancy within the Cascade Range, which includes half of the U.S. volcanoes designated by the U.S. Geological Survey as “very high threat.” The team found that all of the volcanoes, including dormant ones, have persistent and large magma bodies.

The study, led by postdoctoral researcher Guanning Pang, was published in Nature Geoscience and co-authored by Geoffrey Abers, professor in geological sciences.