Deep in Bolivia’s remote Andes, the majestic Uturuncu volcano has long been a source of scientific fascination—and public intrigue. Dubbed a “zombie” volcano because of its apparent geological reawakening, Uturuncu hasn’t erupted in nearly 250,000 years. Yet satellite data and seismic signals have shown strange signs of life over the past few decades, raising questions and occasional alarm: Is this dormant giant coming back to life?
A new study led by researchers at the University of Oxford, in collaboration with Cornell University and Chinese institutions, offers the clearest look yet into the volcano’s internal anatomy. And the good news? Uturuncu is restless, but it’s not reanimating in the apocalyptic sense.
Using advanced seismic tomography—a method similar in principle to a CT scan—the research team analyzed more than 1,700 earthquake signals to create a 3D map of the structures beneath the volcano. Combined with geochemical rock analysis, the findings revealed a complex but stable subsurface environment. The main takeaway: the cause of Uturuncu’s recent “unrest” lies not in magma movement, but in the slow migration of hydrothermal fluids and gases.
This discovery helps resolve a puzzle that has nagged at volcanologists for years: the “sombrero uplift” effect seen on satellite images. This uplift—a gradual bulging of the ground around the volcano—has been interpreted by some as a sign that magma could be accumulating and preparing to erupt. But the new data points to a more benign explanation. Fluids are pooling and pressurizing within the shallow crust, causing the surface to slowly rise, without any imminent threat of eruption.
“Our results show how linked geophysical and geological methods can be used to better understand volcanoes and the risks they pose,” said Professor Mike Kendall, a geophysicist at the University of Oxford and co-author of the study.
Interestingly, Uturuncu sits atop the largest known magma body in the Earth’s crust—the Altiplano-Puna Volcanic Complex. But that massive reservoir lies much deeper than the signals of surface unrest. While it’s awe-inspiring to think of that much molten rock beneath the Earth’s surface, it’s not actively threatening the local communities that live nearby.
The study also reinforces a broader point: not all volcanic signals mean eruption. Volcanoes, like people, can be noisy and active without being dangerous. Understanding the true cause of a volcano’s signals—whether magma, gas, or water—is key to managing risk and avoiding false alarms.
For Uturuncu, this research brings reassurance. While its nickname may conjure images of a volcano returning from the dead, the truth is more nuanced—and far less ominous. Thanks to cutting-edge science, we now know this “zombie” is stirring in its sleep, not rising from the grave.
Read More: New study reveals the anatomy of Uturuncu, the “zombie” volcano | University of Oxford
