New Model Reveals Mechanisms Behind Stealthy Volcano Eruptions

In a groundbreaking study, researchers from the University of Illinois have unveiled a predictive model that elucidates the enigmatic behavior of "stealthy" volcanoes, which can erupt without prior warning signs. Volcanoes typically display precursors such as ground swelling or minor seismic activity that indicate impending eruptions. However, some, like Veniaminof in Alaska's Aleutian Arc, can remain dormant until the moment of eruption, posing significant risks to nearby communities and air traffic.

Dr. Yuyu Li, the lead author of the study published in *Frontiers in Earth Science* on June 12, 2025, emphasizes, "Despite major advances in monitoring, some volcanoes erupt with little or no detectable precursors, significantly increasing the risk to nearby populations." The researchers focused on Veniaminof, which has had 13 eruptions since 1993, with only two showing adequate warning signs. For instance, during its 2021 eruption, signs were detected three days after the event began.

Veniaminof represents a crucial case study in understanding why some volcanoes can erupt without warning. According to Dr. Li, "It is one of the most active volcanoes in Alaska," and the study revealed that internal conditions, such as low magma supply and warm host rock, contribute to these stealthy eruptions. The researchers collected data leading up to Veniaminof's 2018 eruption, which was similarly stealthy. They constructed computer models to replicate various volcanic scenarios, adjusting parameters such as the size and shape of the magma chamber, its depth, and the rate of magma flow.

Their findings indicated that a significant flow of magma into a large chamber typically causes ground swelling, which serves as a visible warning. Conversely, when magma flows slowly into a small chamber, eruptions can occur with minimal indications. The simulations also highlighted the influence of chamber geometry; broader chambers might result in subtle seismic activities, while narrow chambers could cause only minor ground shifts.

Temperature also plays a crucial role in eruption dynamics. The study found that prolonged magma presence can heat surrounding rock, which reduces the likelihood of cracking or ground movement — two key signs that scientists monitor. Dr. Li states, "In warm rock, an eruption can be all but silent."

To mitigate the risks associated with these unpredictable eruptions, the researchers advocate for enhanced monitoring methods. Dr. Li recommends the integration of advanced tools, such as borehole tiltmeters and infrasound monitoring, to detect subtle changes in volcanic behavior. "Combining these models with real-time observations represents a promising direction for improving volcano forecasting," she asserts, suggesting that such an approach could lead to more effective responses to protect communities at risk.

The implications of this research extend beyond Veniaminof. Volcanoes like Popocatépetl and Colima in Mexico, Merapi in Indonesia, and Stromboli in Italy also exhibit similar stealthy behaviors. Understanding the conditions that contribute to these eruptions is vital for disaster preparedness and risk management in populated regions near these geological features.

In summary, the work conducted by the University of Illinois provides a deeper understanding of the mechanisms behind stealthy volcano eruptions. By enhancing monitoring techniques and integrating new scientific models, researchers hope to minimize the dangers posed by these unpredictable natural events, ultimately safeguarding lives and infrastructure in vulnerable areas.