Lanin volcano (Chile / Argentina): seismic unrest, alert level raised
Increased seismic activity triggered SERNAGEOMIN to raise the alert status of the volcano to yellow.
Fri, 17 Feb 2017, 12:0512:05 PM | BY: T
Starting 15 February, a significant number of earthquakes occurred under the volcano, both including volcano-tectonic quakes, indicators of internal rock fracturing often caused by intruding fluids (e.g. magma), and long period quakes, thought to be caused by internal fluid movements.
Whether or not these are signs of possible new eruptive activity under the volcano in the medium to long-term future (several months to years to decades) is matter of speculation.
Lanin stratovolcano, located on the Chile-Argentina border about 150 km east-northeast of Valdivia (Chile), has no known historic eruptive activity. However, it is considered active; based on geologic studies, it is thought to have had its last eruption only about 1500 years ago, producing a cinder cone and a lava flow from a flank vent on the south-west slope.
Wed, 15 Feb 2017, 06:00
Lanin volcano (Central Chile-Argentina border) - Smithsonian / USGS Weekly Volcanic Activity Report for 15 February-21 February 2017 (New Activity / Unrest)
Servicio Nacional de Geología and Minería (SERNAGEOMIN) Observatorio Volcanológico de Los Andes del Sur (OVDAS) reported that beginning at 1524 on 15 February a seismic swarm at Lanin, consisting of 59 volcanic-tectonic, long-period, and spasmodic tremor events, lasted for 45 minutes. The largest volcano-tectonic event was a M 1.8. The Alert Level was raised to Yellow (second highest level on a four-color scale); ONEMI declared an Alert Level Yellow (the middle level on a three-color scale) for the community of Curarrehue (32 km N). ... Read all