Siren blasts created great concern in the southern Chilean town of Pucón on the afternoon of Easter Sunday. The residents feared that a second eruption of Mount Villarrica, a large glacier-covered volcano close to the town, would occur at any moment. The dramatic lava flows and enormous ash clouds from the first eruption on March 3 were fresh in their minds. And other events Sunday morning—noisy explosions, a large new ash-cloud—had put residents on edge.
This volcano, 2840 meters in height, has erupted a number of times over the centuries, and is well-known as one of the most active volcanoes in Chile. The glaciers that form the ice cap on its summit create significant risks. This ice cap, about 40 square kilometers in area, could release large volumes of water if lava reached it directly, sending large flows of ash, mud and debris rushing down the mountain to nearby agricultural areas and towns.
Two hours after the alarm, the municipality of Pucón issued a statement that “the sirens that were activated in Pucón were only providing a preventive measure, and were not intended to evacuate the town, but only to alert residents, because of the greater activity of the volcano.” The officials went on to say that one national agency has retained its warning level at yellow, and another at orange, as they both have for some days, so that circumstances had not changed in any serious way. The sirens, they said, were simply a reminder to stay alert in case there was a shift in the risk.
The first agency is the ONEMI, the National Emergency Office, a branch of the Ministry of the Interior and Public Security. Their official statement stated that there was little risk of a serious eruption of lava. They offered the comment that the globs of lava that were shooting from the crater were traveling at most 200 meters, a distance which they deemed safe. They based their assessment on recent visual observations of the volcano and on the reports of the second agency, OVDAS, the Volcanic Observatory of the Southern Andes, a branch of the National Service of Geology and Mining (itself a branch of the Ministry of Mining). This agency maintains 8 seismographs on the volcano, as well as 4 GPS stations, 2 instruments to measure sulfur dioxide concentrations, 4 webcams, a microphone to record sounds and other instruments to measure surface movements. (You can see the webcams here.)
— PublimetroChile (@PublimetroChile) April 5, 2015
In a statement today, Carlos Cardona, the OVDAS representative, emphasized that there was little change in the level of seismic activity, the most important precursor of eruptions, though he also stressed that the volcano was unstable, the situation could change, and that he and his associates were closely tracking the data that came in from their instruments. These comments might not have provided much assurance to the town officials and residents, who heard the loud booms of explosions and saw the ash clouds.
A number of the town’s residents resented what they felt was a false alarm on the part of the official who sounded the alarms from the fire station. They provided ample testimony of their views on the municipality’s Facebook page. Several described how restaurants and supermarkets closed, how the staff at the local prison did not know what to do, and how the parents of children who board in Pucón during the week and return home to outlying villages on weekends were also uncertain whether to send their children back to school. Several people mentioned the story of the boy who cried wolf (in Chile, this boy is named Pedro). Andrea Handal Tarud wrote, “But your official procedures state that the sirens sound to tell people to EVACUATE, how can we know if it’s a preventive alert or real? Be serious, don’t break your own procedures, with that you only confuse people and alarm them unnecessarily.”
“What a way to confuse people!” Heide Hillis wrote. “The few tourists who were around rushed from Pucón, and the local people were panic-stricken. HORRIBLE management of the situation.”
Perhaps the two agencies, ONEMI and OVDAS, will follow the suggestion of another resident, Flor Vega Lagos, who directed them, in her Facebook comment, to come to an agreement on the level of the alert. It seems more likely that local residents and national agencies alike will continue to scrutinize the multiple and changing signs of the volcano, each forming their own judgment.
To learn more about the eruption of Villarrica in March, look here.