VILLARICA – On September 9, the national service of geology and mining (SERNAGEOMIN) observed abnormally high seismic signals at Villarrica volcano. The level and type of seismicity were sufficient to raise the threat level for the volcano from yellow to orange. Earlier this year, the volcano already produced some weaker eruptions.
The Villarrica volcano is one of the few volcanoes worldwide with a quasi-permanent summit lava lake inside the 200 m wide crater, and the recent seismicity also came with a change in the level of the lava lake. Both events could result from blockages in the channel that feeds the lava lake. A blockage would allow the build-up of pressure that could result in an explosive eruption.
As a preventive measure, officials set up a 2 km exclusion zone around the crater. The parameters of the zone are based on data from the 2015 eruption, when the volcano ejected pyroclastic material around the summit. This eruption also produced floods of volcanic material, or lahars, that flowed down the slopes.
VOLCÁN VILLARRICA: Informamos que debido a un aumento del RSAM (amplitud de la señal sísmica) y con una tendencia al alza se ha decidido declarar la alerta técnica #Naranja para el volcán Villarrica, lo que implica un radio de exclusión de 2 km en torno al cráter. @onemichile pic.twitter.com/k5BMieXii0
— Sernageomin (@Sernageomin) September 9, 2019
Preparing for Any Event
Alert levels are usually raised to aid preparation for possible evacuations. This is especially important given the popularity of the areas around the Villarrica volcano. But the exclusion zone near the summit aside, no other measures were taken so far, and most activities around the volcano continue normally. With the exclusion zone, however, summit climbing, popular among tourists who want to see the lava lake, is being suspended.
Two other volcanoes have currently high alert levels, Nevados de Chillán and Copahue volcano. The former has been in a state of intermittent eruptive activity for several months while the latter is at yellow alert level, meaning it is being intensely monitored for any changes. This is especially important as it is one of the highest risk volcanoes in the region.
For Planchón-Peteroa the alert level has been reduced to green, following minor but sustained eruptions in February. All other volcanoes in Chile are also at the green level.
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John is a volcanologist, sports fan, radio broadcaster, and accomplished musician. Born and raised in Britain, he has travelled extensively for his research on volcanoes. Whilst living in London, UK, John performed in the punk bands ‘And Now We’re Even’ and ‘Filthy Militia’ recording six studio albums and two EP’S over this time. He currently lives in Santiago, Chile where he works as a university professor in rock mechanics.