Bolivia’s “Zombie Volcano” shows signs of activity and can wake up

Can a volcano resurrect from the dead? Uturuncu, a high peak in the central Andes, is known as a “zombie volcano”. Although it has not been erupted for over 250,000 years, it still has signs of activity similar to those observed in active volcanoes, such as gas plumes and earthquakes.

Satellite radar images made more than two decades of Uturuncu – the highest mountain in southwest Bolivia – showed that forces inside the volcano elevated and then lowered a region near the summit measuring about 150 kilometers wide, creating a shadow -like form. Scientists recently examined Uturuncu more closely to verify that continuous deformation and other activities were signs that the sleeping volcano could be awakening.

Combining satellite data with seismic activity analysis and computational models of how rocks respond to different pressures, researchers set up a clearer image of Uturuncu’s internal anatomy and discovered the cause of their restlessness. They reported their findings on April 28 in the magazine Proceedings of the National Academy of Sciences.

Volcanic eruptions usually occur when magma below a volcano appears in underground pockets called magmatic chambers and then escapes to the surface through openings and fissures. Eruptions are more explosive when the magma is thicker, imprisoning gases until the pressure increases and then suddenly released, expelling magma as washing hard.

But this was not the case under Uturuncu, according to the study. Instead, magma, gases, and saline fluids were interacting in a hydrothermal network – a system with activities that were not fully understood – to produce the noise zombies of the volcano.

Releasing steam

Under Uturuncu, at a depth of about 10 to 20 kilometers, is a vast magma reservoir called the magmatic altiplane-pune. With approximately 200 kilometers long, it is the largest active magmatic body known in the earth’s crust. Previous studies have suggested the existence of an active hydrothermal system by linking the magma reservoir and the mountain range above, but it was not known how magma and fluids interacted within this network.

Using signs of more than 1,700 seismic events between 2009 and 2012, scientists produced high resolution images of the rasa crust under Uturuncu. They also registered underground electrical and gravitational changes and changes in rock chemistry, revealing details never seen from the channel system under and inside the volcano while geotermicly heated fluid circulated.

The researchers found that, as the magmatic body warmed the underground liquid and released gases, gas and liquid migrated up and accumulated in cameras below volcanic crater. His movement through Uturuncu triggered tremors, released steam, and deformed the volcano rock, causing superficial elevation of about 1 centimeter per year.

Uturuncu’s internal dynamics not only explains its activity, but it also suggests that this zombie will not resurrect anytime soon, said study co -author Dr. Mike Kendall, professor and head of the Earth Sciences Department at Oxford University.

“We are not seeing seismicity increasing progressively. A bad signal would be an increase in seismicity, and then a seismicity that is beginning to migrate from great depth to much shallower depths – this is usually an indication that magma is moving,” Kendall told the CNN .

“We are not seeing any of this,” he said. “It seems that it is just the volcano wearing, releasing steam and calming down, if it’s doing something.”

The use of multiple techniques was essential to highlight Uturuncu’s underground structure, according to geologist Benjamin Andrews, director of the Global Vulcanism Program of the National History Museum of Smithsonian Institute in Washington, DC.

In isolation, the methods that investigate seismic, chemical and physical activity of rocks “would give interesting but somewhat ambiguous results,” said Andrews, who was not involved in the study. Together, these methods point to a hydrothermal system rather than the moving magma, such as the cause of Uturuncu’s activity, and provide an overview of the interaction between magma, rock and fluid under volcanoes.

“This research is important for the understanding of volcanoes, granitic rocks, ore bodies and the formation of the continental crust,” Andrews said by email. It is also important to recognize that some volcanoes can be quite active “but not necessarily be prepared to erupted.”

Dozens of zombies

Over the decades, the global Vulcanism program has recorded about 50 zombie volcanoes over 12,000 years old, but less than 2.6 million years. Its signs of activity are “mainly geothermal characteristics such as thermal and smoke sources (openings where hot gases escape),” said study co -author Matthew Pritchard, professor of geophysics at Cornell University in New York.

Because Uturuncu is one of many zombies volcanoes scientists are monitoring around the world, new findings can help identify which zombies risk erupting. Some zombies show high surface temperatures and are already being explored as potential geothermal energy sources, as well as their mineral deposits, “but many are still ready for additional investigations,” Pritchard told the CNN by email.

“Some may be in a long and slow decline, just cooling from warmer previous periods. Others may eventually have some increase in activity,” he said. “But we still don’t know how to differentiate them.”

Observing the internal system of a volcano could reveal possible targets for using geothermal energy and access to essential metals for technologies such as copper, nickel and platinum, Kendall added. And this method combination could be useful for analyzing any type of volcano – not just zombies.

“It’s a really good way to better understand the anatomy of a volcano, when developmental stage it is,” he said. “This is very important for risk assessment and dangers.”

See also: Spectacular images show Kilauea volcano erupting in Hawaii

Next massive mass eruption can cause chaos, scientists say

This content was originally published in Bolivia’s “Zombie Volcano” shows signs of activity and can wake up on CNN Brazil.

Source: CNN Brasil