Report on Nevados de Chillan (Chile) — 16 November-22 November 2016
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 16 November-22 November 2016
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2016. Report on Nevados de Chillan (Chile) (Sennert, S, ed.). Weekly Volcanic Activity Report, 16 November-22 November 2016. Smithsonian Institution and US Geological Survey.
Nevados de Chillan
36.868°S, 71.378°W; summit elev. 3180 m
All times are local (unless otherwise noted)
The Buenos Aires VAAC reported that on 18 November an ash puff from Nevados de Chillán was recorded by the webcam. SERNAGEOMIN reported that two explosions, detected at 0536 on 18 November, generated a plume that rose 1.2 km above the crater rim.
Geological Summary. The compound volcano of Nevados de Chillán is one of the most active of the Central Andes. Three late-Pleistocene to Holocene stratovolcanoes were constructed along a NNW-SSE line within three nested Pleistocene calderas, which produced ignimbrite sheets extending more than 100 km into the Central Depression of Chile. The dominantly andesitic Cerro Blanco (Volcán Nevado) stratovolcano is located at the NW end of the massif. Volcán Viejo (Volcán Chillán), which was the main active vent during the 17th-19th centuries, occupies the SE end. The Volcán Nuevo lava-dome complex formed during 1906-1945 on the NW flank of Viejo. The Volcán Arrau dome complex was then constructed on the SE side of Volcán Nuevo between 1973 and 1986, and eventually exceeded its height. Smaller domes or cones are present in the 5-km valley between the two major edifices.