Several explosions, seismic activity and a large ash plume has local residents worried about the volcano known as Nevado del Ruiz. The last eruption cost the lives of more than 20,000 people and wiped a small town from existence. What is actually happening with this volcano situated between Pereira and Manizales in the Coffee Axis of Colombia?
This is the question I will try to answer based on what little information I have been able to glean from the Facebook page for the Manizales seismic institute, local information and my own estimation of events which are taking place. I am also going to delve into the history of the volcano itself to give a better picture of the events which have been unfolding since Sunday.
Nevado del Ruiz is what we would call a “Stratovolcano.” This classification means that it is built up from many layers of strata, or all the fun trappings of a volcano: ash, pumice, hardened lava and tephra (fragmented material resulting from previous eruptions). This type of volcano is characterized by explosive eruptions or effusive eruptions.
Which would you prefer? Giant explosions or fast flowing lava? Tough questions. To give even more perspective, Mount St. Helens in Washington, USA was a stratovolcano. Since there is also snow up there, if an eruption were to happen the flow will come streaming down quite fast due to the water which will create a lot of mud and bring with it debris. When this happens the scientific dudes call it a “pyroclastic flow.”
This is a risk to about 500,000 people currently inhabiting the region.
The most important historical event that we need to be aware of happened in 1985 (Hey that was the year I was born!!). Unfortunately this is the sad part of the story I am telling. The seismic/volcano people-in-the-know judged the risk of the pyroclastic flows to be quite high in a report released in October.
At this time the activity decreased and nothing was done about the report. Just a few weeks later on November 13th the mountain began to erupt, flinging tephra, magma, the works 30 Km into the air (about 18 miles high). On the surface this wasn’t so bad cause the 35 million tons of lava stuff was only 3% of the St. Helens eruption in 1980. However, things got real when 4 pyroclastic flows rushed down the river valleys gaining speed and momentum.
This eruption wiped the small town of Armero and three fourths of its population. The reason cited for this tragedy was that the “authorities” refused to start the costly preventative operations without a “clear sign” of imminent danger. Maybe they wanted it spelled out in big letters in the sky. So the mayor and the local priest told everyone to just chill out…no danger. Their bad.
A terrible miscalculation which cost the lives of more than 20,000 people.
Travel Alert Nevado del Ruiz
Since 2010 Nevado del Ruiz has been showing signs of activity. In 2012 there was a bit of a small hiccup type eruption causing some ash, explosions and a red alert causing evacuations. This activity continued until August of 2012. So where does all this activity leave us?
- The Colombian Observatory of Volcanology and Seismology has monitoring equipment installed on the mountain measuring movement between fault lines, platelets and the crater.
- After the disaster of 1985, a special program was created to promote preparedness planning and prevent further disasters.
- Accidents still do happen, but it’s a matter of vigilance and awareness. At this time the observatory is staying mum about the recent ash clouds much to the consternation of locals.
- Nevado del Ruiz doesn’t have to have a big eruption to become extremely dangerous due to the fast moving mud flows which can emerge from the glacier.
- If you are ever hiking or camping in an area which begins to have a significant amount of seismic activity, don’t hesitate to leave until safety is confirmed and err on the side of caution.
The Colombian government and its agencies claim preparedness. Will these same agencies act in time or get lost in a mess of bureaucracy and lack of funds to respond? There is no telling. Nevado del Ruiz may become more active as this year has seen a previously unmatched rise in volcanic activity worldwide in comparison to other years. Below are source links and additional information to help you decide the risk:
Colombian Geologic Service: http://www2.sgc.gov.co/Manizales.aspx
Photo Credit: Servicio Geologico de Colombia
WARNING: THE FOLLOWING VIDEO HAS GRAPHIC SCENES FROM THE LAST VOLCANIC ERUPTION. NOT FOR SMALL CHILDREN OR WEAK CONSTITUTIONS.