This was a volcanic eruption that devastated Armero and killed 23,000 people.

Colombia’s Nevado del Ruiz is one of the northernmost active volcanoes in the Andean volcanic belt. It has been active for about 1.8 million years. But if there is one moment of activity that will go down in history, it is the eruption of November 13, 1985. Forty years ago, Nevado del Ruiz destroyed Armero.

We are in the interior of Colombia, in the so-called northern region. Armero is located 48 km from Nevado del Ruiz and 169 km from the capital Bogotá. the volcano was already there at that time One of the most active countries in South America. Along with Galeras, they are the most active in Japan.

In 1985, Almelo, with a population of 29,000, was the capital of the province of Tolima. Today is Guayabal. The tragedy that occurred on the night of Wednesday, November 13th of that year marked a dramatic change in the history of the municipality. Armero disappears, approximately 23,000 killed. The eruption also seriously affected the cities of Villamaria and Chinchina.

Signs and warnings are ignored

Already on the 11th, Nevado del Ruiz was beginning to show signs of intense life. “Previously, volcanoes were constantly emitting ash, I have already reported the activity” he said snail radio Carlos Arturo Osorio was the head of the radio station’s transmitters in 1985.

As if to declare his abilities, he released a large amount of ash. However, the volcano remained dormant for 69 years.. Who would have thought of that…not the population, but some scientific organizations. Volcanologists had reported signs of volcanic activity since December of the previous year.

A mission from the United Nations Disaster Relief Coordinator’s Office (UNDRO) visited the volcano in March 1985. Nevado del Ruiz’s activities are abnormal; Typical precursor to a major eruption It recommended starting an active monitoring and risk management plan.

On the eve of the September 19 earthquake in Mexico, which killed more than 40,000 people, Ramon Antonio Rodríguez, the mayor of Almelo, called the editorial office of a Colombian newspaper. time. “We have a ticking time bomb here, about 15 kilometers from Armero. The Lagunilla River was dammed more than six months ago, and if the Nevado del Ruiz explodes, they will say: Then Armello is going to put the deadBecause an avalanche of melting snow will burst the dam and destroy us all,” he told journalists.

In October 1985, at the request of the Caldas government, an Italian volcano research team analyzed gas samples from the fumaroles and features. He confirmed that it was a mixture of carbon dioxide and sulfur dioxide, indicating that magma was released directly to the surface. Italian scientists published a report stating: It warned that the risk of mudslides was unusually high.

Mayor Armero wanted to issue a warning to those who can do something in the face of such an emergency. He met with Tolima Governor Eduardo Alzate García and several secretaries. He suggested they evacuate the city. “They all laughed at me,” he later commented.

In early October, the Colombian Congress also discussed the risks in Nevado del Ruiz and Armero. “The minister dared to say this.” The rumored war caused more damage than the ash spewed by a volcano. “It was in the middle of an eruption,” El Tiempo recalls today.

As in 1595 and 1845

In November 1985, volcanic activity increased again as magma approached the surface. The volcano began releasing large amounts of sulfur-rich gases, primarily sulfur dioxide. of Pressure inside the volcano increased due to magma degassing.a space located exactly above the magma that ultimately caused an explosive eruption.

Experts already knew a lot about what a Nevado del Ruiz eruption would be like. Mainly explosiveHowever, the Volcanic Explosivity Index (VEI) is moderate at 3-4 on a scale of 0-8. When this volcano exploded, it created a rapid flow of pyroclastic flow, a mixture of rock and hot gases.

These eruptions, even of moderate size, melt the volcano’s vast ice sheets. Occurrence of mudflows, large-scale mudflows, and debris flows. These represent serious threats to human life and the environment. This has already happened in 1595 and 1845, and it happened again on November 13, 1985.

“That night, when I was alone in the hut, I felt something falling on the door. I thought it was a soldier leaning against the sentry box, but when I went outside I saw nothing. Then I heard the sound of falling stones and pyroclastic flow (…) I knew it was Nevado del Ruiz. I congratulated myself and thought I had come this far.” Osorio says today.

Moderate but destructive eruption

The volcano erupted at 9:09 p.m., releasing more than 30 kilometers of dacite tephra into the atmosphere. Total mass of ejected material including magma It was 35 million tons. The mass of sulfur dioxide emitted was approximately 700,000 tons.

That night, a moderate-sized (VEI 3) Vulcanian eruption occurred. The eruption produced a pyroclastic flow of melted glaciers and snow, creating four lahar flows down the volcano’s slopes. These largest flows completely destroyed Armero. For years, there had been reckless use of the land, with many homes being built where mudslides were likely to wash away. The river destroyed the town, first flowing water, then mud, and finally lava.

The 300-ton rock dragged over 16 kilometers is a testament to the strength of the torrent. “I felt strong sulfur smellthe fog was low and the ash continued to fall. “After the big eruption, there were two or three other smaller eruptions, but they were just as strong,” Osorio told a Colombian radio station.

3,000 more deaths in Villamaria and Chinchina

At least 23,000 people died, according to the Colombian Disaster Research Commission (other sources citing local media) they increase that number to 25,000). Another 3,000 people died in Villamaria and Chinchina, in the province of Caldas.

Complete devastation, farms, livestock, houses, everything covered… It was as if the land had been paved over. ”

“The next day, when the sky cleared, There was complete devastation, Vanished farms, livestock, houses, everything was covered. “It was a desolate landscape, as if the land had been paved over,” Osorio says today.

Nevado del Ruiz tragedy considered a volcanic disaster The deadliest death toll in South America in the 20th century It is the fourth largest in the world since the 16th century.