Latest news with #MikeKendall
Express Tribune
06-05-2025
- Science
- Express Tribune
Zombie volcano stirs after 250,000 years of dormancy: Scientists explore
Listen to article The Uturuncu volcano in Bolivia's Andes Mountains, dormant for 250,000 years, is exhibiting warning signs of a potential eruption that could threaten lives and cause destruction. Uturuncu, the highest mountain in southwestern Bolivia, caused a region near its summit—about 150 kilometers (93 miles) wide—to rise and fall, creating a sombrero-like shape. Over 1,700 recent earthquakes have prompted scientists to study Uturuncu. By integrating satellite data, seismic analysis, and computer models of rock behaviour under pressure, researchers have gained a clearer understanding of the internal workings of Uturuncu, uncovering the cause of its unusual activity. Their findings were published on April 28 in the Proceedings of the National Academy of Sciences. Volcanic eruptions generally happen when magma rises into underground pockets known as magma chambers and escapes through vents or fissures to the surface. The eruptions tend to be more violent when the magma is thicker, as it traps gases that build up pressure, which is then released explosively, sending magma shooting out as lava. However, this isn't the case beneath Uturuncu, as the study reveals. Instead, magma, gases, and briny fluids are interacting within a hydrothermal system—an activity not entirely understood—to cause the volcano's "zombie" rumblings. Beneath Uturuncu, at depths ranging from 10 to 20 kilometres (6 to 12 miles), lies the Altiplano-Puna Magma Body, a vast magma reservoir spanning about 200 kilometres (124 miles). It is the largest known active magma body in the Earth's crust. Previous studies suggested an active hydrothermal system linking this magma reservoir to the mountain above, but the precise interaction between magma and fluids remained unclear. The study revealed that as the magma body heated underground liquids and released gases, these fluids and gases moved upwards, collecting in chambers beneath the crater. This movement triggered seismic activity, released steam, and caused the volcano's rock to deform, leading to a surface rise of approximately 1 centimetre (0.4 inches) annually. While these internal processes explain Uturuncu's activity, the study suggests that the "zombie" volcano is unlikely to erupt anytime soon. Dr. Mike Kendall, coauthor of the study and professor at the University of Oxford, reassured that there are no alarming signs. "We're not seeing seismicity increasing or migrating from great depths, which would indicate magma movement," he explained. "It seems the volcano is simply releasing gas and calming down. The Global Volcanism Program has tracked about 50 "zombie" volcanoes, ranging from 12,000 to 2.6 million years old, mostly showing geothermal features like hot springs and fumaroles. Uturuncu, along with others, could help identify those at risk of eruption. Some have higher surface temperatures and are explored for geothermal energy and mineral deposits. "Many still require further investigation," says Dr. Matthew Pritchard from Cornell University. "Some may be cooling, while others might increase in activity," he adds.
30-04-2025
- Science
Scientists solve mystery of 'zombie' volcano displaying signs of eruption for decades
Researchers have solved the mystery on why a South American "zombie" volcano has displayed possible signs of an eruption for decades. The Uturuncu, a dormant volcano located in the Andes mountains in Bolivia, has not erupted in 250,000 years. But signs of unrest at the site -- including earthquakes and plumes of gases -- prompted researchers to look into whether a possible eruption is imminent. Since the 1990s, the ground around Uturuncu has appeared to deform in a "sombrero" pattern, with the land in the center of the volcanic system rising up and surrounding areas sinking down, satellite radar and GPS measurements have shown, according to a study published in the Proceedings of the National Academy of Sciences on Monday. Over the last 50 years, the central rising measured at uplifting rates up to 0.4 inches per year. Scientists from the U.S., the U.K. and China combined seismology, physics models and analysis of rock composition to identify the cause of the unrest. By visualizing the way that magma and gases move around underneath the volcano, they determined that the rumblings and other signs of unrest were the result of the movement of liquid and gas beneath the crater, according to the paper. An eruption at Uturuncu -- which sits above the world's largest-known magma body in the Earth's crust -- could cause widespread damage and threaten human lives for local populations, the researchers said. However, there is a low likelihood of explosion, they concluded. The researchers compared the imaging of the interior of the volcano to methods used in medical imaging of the human body. Seismic waves provided high-resolution insights into the inner workings of Uturuncu -- and in three dimensions, according to the paper. The imaging let researchers map out possible pathways for geothermally heated fluids to migrate upwards, as well as how liquids and gases accumulate in reservoirs directly below the volcano's crater. This activity is most likely the cause for the deformation at the center of the volcanic system, the paper notes. "Our results show how linked geophysical and geological methods can be used to better understand volcanoes, and the hazards and potential resources they present," co-author Mike Kendall, head of the University of Oxford's department of earth sciences, said in a statement. The methods could be applied to more than 1,400 potentially active volcanoes around the world, as well as dozens of volcanoes that are not considered active but show signs of life, co-author Matthew Pritchard, a geophysicist at Cornell University, noted in a statement.
