Today I’m going to tell you a moving story that I stumbled across while researching the mountains of Los Nevados after my trip to Colombia over the new year. It concerns a 13-year old girl called Omayra Sanchez whose plight came to worldwide attention following the eruption of Nevado del Ruiz in 1985.
Nevado del Ruiz (5,325m) is an active volcano in Colombia’s Cordillera Central mountain range, and the highest mountain in Los Nevados National Park. At the time of my visit, it was sufficiently active that it was considered too dangerous to climb. On my first evening in Los Nevados, we observed it belching gas from a hillside above our lodge.
In fact, on 13 November 1985 Nevado del Ruiz was responsible for South America’s deadliest ever volcano eruption, when the town of Armero 50 kilometres to the east was wiped out and as many as 25,000 people lost their lives.
The incident was doubly tragic because authorities had ample warning of an imminent eruption and its likely impact, but failed to act.
As early as December 1984, three significant earthquakes within 30km of Nevado del Ruiz’s summit led to increased volcanic activity. This included the formation of a new crater within the existing main crater, the Crater Arenas, which was observed by geologists in January 1985.
In March a UN seismologist visited and observed a 150m vapour column erupting from the mountain which he concluded was a typical precursor of “an eruption of magnitude”. Earthquakes continued through 1985 and in September a state of alert was declared after a small eruption.
In October, geologists published a hazard map that indicated that Armero could be completed flooded in the event of a major eruption. The map met with criticism for being “too alarming”.
In fact, the reality was much worse. Glaciated volcanoes such as Nevado del Ruiz are especially dangerous because the heat from an eruption melts the ice and causes lahars – deadly rivers of mud, ice, rocks and other volcanic debris. These travel rapidly and wipe out all in their path with a wall of water and debris.