One of South America's Most Active Volcanoes Could Be at Risk of Partial Collapse, Study Suggests

Scientists have detected early warning signs that one of the most active and dangerous volcanoes in South America—according to the United States Geological Survey—is at risk of suffering a partial collapse, a process that could result in a large landslide.

According to a study published in the journal Earth & Planetary Science Letters, recent activity has destabilized the western flank of Tungurahua—whose name means "Throat of Fire" in the language of the indigenous Quechua peoples.

The volcano—located around 85 miles south of Ecuador's capital in the Andes mountains—has been frequently active since 1999, when eruptions forced the evacuation of around 25,000 people from the surrounding areas. Another ancient eruption around 3,000 years ago led to a partial collapse of Tungurahua's western flank.

This collapse led to a landslide that spread debris over an area equivalent to around 30 square miles. Over the course of subsequent millennia, the volcano gradually rebuilt itself, eventually reaching its current height of around 16,500 feet.

But the recent ongoing volcanic activity has led to significant deformation on Tungurahua's surface, particularly in the amphitheater-shaped scar left over from the 3000-year-old collapse of the western flank.

According to the authors of the latest study, this rapid deformation is the result of geological processes taking place inside the volcano.

"Using satellite data we have observed very rapid deformation of Tungurahua's west flank, which our research suggests is caused by imbalances between magma being supplied and magma being erupted," James Hickey, lead author of the study from the University of Exeter in the U.K., said in a statement.

"[The west flank of the volcano] was uplifted by roughly 3.5 centimeters [1.38 inches] over a three-week period, while the other flanks remained stable," Hickey told Newsweek.

Specifically, the deformation of the west flank can be explained by the temporary storage of magma beneath the surface. This magma eventually supplies eruptions. But the researchers noted the signs they have observed do not definitively mean a collapse of the western flank is inevitable.

The Tungurahua volcano spews fumes and lava on February 27, 2016 in Huambalo, Ecuador, affecting neighboring parishes with ashfall. JUAN CEVALLOS/AFP via Getty Images

"Magma supply is one of a number of factors that can cause or contribute to volcanic flank instability, so while there is a risk of possible flank collapse, the uncertainty of these natural systems also means it could remain stable. However, it's definitely one to keep an eye on in the future," Hickey said in a statement.

In light of the latest results, the researchers recommend that the volcano should be closely monitored for any further signs that the western flank could collapse.

"The damage a potential flank collapse could have on the surrounding area depends on how the volcano continues to behave, this is why it is important that scientists continue to keep a close eye on the volcano and this is exactly what the Instituto Geofísico in Ecuador are doing," Hickey told Newsweek.

The team says the findings could help to better understand flank instability in other volcanoes around the world that display surface deformation in particular areas.