Unveiling Yellowstone: Fresh Discoveries on the Enigmatic Magma Reservoirs Beneath the Surface

HILO, Hawaii — Investigators from the U.S. Geological Survey and Oregon State University explored the area beneath the Yellowstone Volcanic system, discovering that while an eruption is improbable in the region, alterations in the northeastern sector of the volcanic system will be crucial for comprehending future eruptions.

Experts at USGS have charted subterranean areas that contain magma within this volcanic framework. Knowing where magma resides is vital for anticipating volcanic activity and informing the public about possible dangers. This investigation provided a comprehensive view of how magma is distributed throughout the crust at Yellowstone by employing a technique highly responsive to magma presence, serving as an excellent instrument for imaging volcanic systems. The technique utilizes the Earth’s natural electromagnetic field. In Yellowstone, recognized as the largest volcanic system in the United States, this magma mapping method has enhanced the understanding of potential changes within the system in the future.

Researchers mapped rhyolitic magma, a type of molten rock that has triggered prior explosive eruptions in Yellowstone. The findings indicated that the proportion of this rhyolitic magma across the Yellowstone Volcanic system is minimal, suggesting that an eruption anywhere is improbable. However, a section in the northeastern part of the Yellowstone Volcanic system does have the potential to generate additional rhyolitic magma due to an underground heat source known as crustal basalt located there.

“The northeastern area has a direct link to a crustal basaltic heat source underneath it, which can support the production of more rhyolitic magma in that region. This could imply that someday, although certainly not now, there could be sufficient rhyolitic magma to trigger eruptive events in the northeast,” stated Ninfa Bennington, a geophysicist at USGS and the primary author of the study. “We can infer from our findings that while volcanic activity in the western part of Yellowstone may be diminishing, future activity might concentrate in the northeastern sector. This insight is essential for evaluating potential volcanic threats in the area.”

Adam Schultz, a professor of geophysics at Oregon State University and a collaborator on the project, noted that the results emphasize that volcanoes are dynamic entities, and the magma sources that may lie beneath them change over time and shift.

“What we are observing truly illustrates that movement and development of the magma bodies now that we can visualize them, especially by utilizing the effectiveness of the magnetotelluric imaging method,” Schultz remarked. “This is information that can be utilized by individuals interested in modeling the behaviors of these systems and can aid in efforts to conduct risk evaluations.”

USGS and its collaborators sustain networks of instruments to observe activity at Yellowstone as part of the National Volcano Early Warning System.  USGS is also dedicated to conducting studies that enhance our understanding of the volcanic system and its threats. Discover more in the article published in Nature and on the USGS’s Yellowstone Volcanic Observatory website.