The Deadly Volcano Making Experts Worried

A volcano often considered to be the most dangerous in the Western Hemisphere is giving experts cause for concern.

Over the last month, the Nevado del Ruiz volcano, which stands west of the Colombian capital, Bogotá, at an elevation of 17,457 feet above sea level, has been spewing ash plumes and steam. This indicates that an eruption could take place at any moment.

As of May 1, the volcano has been especially active, the Colombian Geological Service said in a statement. Officials have warned those living around the volcano to evacuate.

Brittany Brand, Director for the Boise State Hazard and Climate Resilience Institute at Boise State University, told Newsweek that Nevado del Ruiz is one of the highest volcanoes in the region.

"Because of that, it's covered in ice and snow and it has a pretty thick glacier ice cap," she said. "And the biggest concern about this is the melting of that ice cap."

"It also has very steep flanks and drainages that open up into communities downstream," Brand said. "And so the biggest concern for this volcano are mud flows, or lahars, which can occur with just a minor eruption. A small eruption of ash or lava can melt enough of that snowcap to produce devastating lahars."

Lahars are destructive mud flows from the slopes of a volcano that can be devastating.

The Nevado del Ruiz volcano was responsible for what is known as the Armero tragedy. On November 13, 1985, the volcano produced an extremely explosive eruption that resulted in the deaths of more than 20,000 people in the town of Armero in what was the second-deadliest volcanic eruption of the 20th century.

For this reason, there is added concern about the volcano and its seismic activity. Even a relatively small eruption could be enough to melt the glacier with potentially devastating consequences.

The area around the volcano is home to many farmers and their families. Despite scientists warning them to evacuate, many have stayed as their livelihood depends on the fertile land.

It is not certain that an eruption will occur—this is difficult to predict with any volcano—but Nevado del Ruiz is displaying some telltale signs.

"We could see a dramatic increase in the earthquakes and swelling of the volcano and the gases coming out, which may indicate a significant eruption, or it might just die off," Brand said. "It's just really difficult to know what's going to happen but at this point, we do know that there are signs of unrest."

Brand said similar activity was observed in 1984 but it was almost a year before there was a significant eruption.

If Nevado del Ruiz does erupt, the situation will be vastly different from 1985. This is because now there are much better warning systems in place so that scientists can inform residents of impending danger.

In the case of the 1985 eruption, Brand said there was "nothing in place for them to be warned."

"The case now, we have seismometers, we've got a volcano monitoring organization so Colombia has volcanologists that monitor these volcanoes, and there will be time a time to warn people to evacuate if a lahar is coming," she said.

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