The National Geology and Mining Service (SERNAGEOMIN) said the yellow alert for volcanic complex Planchón-Peteroa, located in the Maule region.
The measure was adopted as a result of the increase recorded by the systems of volcanic alerts, of the cumulative seismicity in January 2016, exceeding the threshold activity of the volcano.
The SERNAGEOMIN explained that implies the transit of fluids within volcanic conduits, although there is no reports of abnormality on the surface .
« Although the events recorded have low levels of energy, the increase in their occurrence, suggest variations in the level of activity of the volcano. Our experts believe that there is a possibility of appearance of small emissions of ash, so it was ruled the technical changes in the level of volcanic alert level to yellow, said the national director of SERNAGEOMIN Rodrigo Alvarez Seguel.
According to reports from the Volcano Observatory of the southern Andes (OVDAS) belonging to the National Geology and Mining Service (SERNAGEOMIN), based on the analysis of information obtained by observators of the complex and monitoring equipment of Planchon – Peteroa volcano , from Friday, January 15, 2016 was noted an increase in activity, which is manifested by an increasing number of events related to fluid flow in volcanic conduits. During January, there have been 289 earthquakes, mostly low energy. However, there were no marked abnormalities changes on the volcanic complex. While the events above have low energy levels, increasing of their frequency and spectral content suggested changes in the volcano’s base level of activity.
Thus, the SERNAGEOMIN indicates that there is a possibility of appearance of small ash emissions, so we proceed to raising the level of technical volcanic alert to yellow, which corresponds to an active volcano with changes in the behavior of volcanic activity, with a probable eruption within weeks / months.
According to the complementarity of the national civil protection system for volcanic activity, the ONEMI declares yellow alert for the municipalities of Molina, Curico, Romeral and Teno.
Planchón-Peteroa is an elongated complex volcano along the Chile-Argentina border with several overlapping calderas. Activity began in the Pleistocene with construction of the basaltic-andesite to dacitic Volcán Azufre, followed by formation of basaltic and basaltic-andesite Volcán Planchón, 6 km to the north. About 11,500 years ago, much of Azufre and part of Planchón collapsed, forming the massive Río Teno debris avalanche, which traveled 95 km to reach Chile’s Central Valley. Subsequently, Volcán Planchón II was formed. The youngest volcano, andesitic and basaltic-andesite Volcán Peteroa, consists of scattered vents between Azufre and Planchón. Peteroa has been active into historical time and contains a small steaming crater lake. Historical eruptions from the complex have been dominantly explosive, although lava flows were erupted in 1837 and 1937.
January 23, 2016. Planchón-Peteroa, Chile :
Sources : 24 horas. cl, ONEMI , GVP .
Photos : Emol