Researchers discovered movements under “Zombie volcano”

The volcano eruption is preceded by a number of phenomena. In the area of ​​the cone or caldera, increased seismic activity is usually recorded, volcanic gas can be released from the crevices in the ground, and the surface itself can undergo delicate bulges. However, it is difficult to treat them as a sign of an imminent explosion – they can take place for decades before eruption occurs, and in other cases occur just before the explosion.

However, as the study published in the pages of “Processings of the National Academy of Sciences”, under some seemingly inactive volcanoes, there may also be some activity. Researchers discovered this during the observation of the “Zombie volcano” from Bolivia, which recently broke out over 250,000 years ago.

The first sign of activity in the vicinity of the Uturuncu cone was detected over two decades ago during the analysis of the deformation of the Earth's surface via satellite data. During the observation of the Andes band Geophysic Matthew Pritchard noticed many volcanoes considered inactive. The researcher's attention was drawn to the fact that the area directly around the cone was tilted, and a little further from the volcano had traces of deposition.

– It was a really unique type of concentric circles. We didn't know what it was – he said.

In 2009, field broadcasts began in the vicinity of Uturuncu. For three years, scientists recorded seismic activity from 48 seismometric stations, which detected over 1,700 earthquakes. The team also measured changes in the gravitational field and electrical currents underground, as well as analyzed the rock composition of the ground and modeling of rock physics.

The analysis revealed that the movements of melted rocks, moving under the volcano towards the surface, are responsible for the strange removal of the area. The liquids released gas, which collected under the cone, pressing at him. This magic system caused the surface to rise by up to one centimeter a year.

Observation of this phenomenon can help us better understand the processes accompanying volcanism, for example, the formation of metal ores. As Pritchard explained, when the currents flow through the molten rock, they collect minerals along the way, and then set them elsewhere.

– Even if we are not worried about the eruption of this particular volcano in the next few years, we can see in real time the processing. Apparently underground there is activity, which at some point can even be economically useful – said the researcher.

The use of the satellite radar interferometry team has allowed to identify similar “zombie volcanoes” around the world, which still show signs of seismic activity or soil deformation, although they have not exploded for hundreds of thousands of years. Bolivia itself has about a dozen sleeping cones. Pritchard said that he wanted to continue their monitoring in case any of them began to wake up more.

“Uturuncu may not explode, but it may happen with some of his neighbors,” he said.