Logo link to homepage

Report on Nevados de Chillan (Chile) — 15 April-21 April 2020

Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 15 April-21 April 2020
Managing Editor: Sally Kuhn Sennert

Please cite this report as:

Global Volcanism Program, 2020. Report on Nevados de Chillan (Chile). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 15 April-21 April 2020. Smithsonian Institution and US Geological Survey.

Volcano Profile |  Weekly Report (15 April-21 April 2020)


Nevados de Chillan

Chile

36.868°S, 71.378°W; summit elev. 3180 m

All times are local (unless otherwise noted)


ONEMI and SERNAGEOMIN reported that an explosive event at Nevados de Chillán’s Nicanor Crater recorded at 1333 on 21 April was associated with a long-period earthquake signal. The explosion produced a gas-and-ash plume that rose 2.4 km above the vent and drifted SE. The Alert Level remained at Yellow, the second lowest level on a four-color scale, and residents were reminded not to approach the crater within 3 km. ONEMI maintained an Alert Level Yellow (the middle level on a three-color scale) for the communities of Pinto, Coihueco, and San Fabián, and stated that the public should stay at least 3 km away from the crater on the SW flank and 5 km away on the ENE flank.

Geologic Background. 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 largest stratovolcano, dominantly andesitic, Cerro Blanco (Volcán Nevado), is located at the NW end of the group. Volcán Viejo (Volcán Chillán), which was the main active vent during the 17th-19th centuries, occupies the SE end. The new Volcán Nuevo lava-dome complex formed between 1906 and 1945 between the two volcanoes and grew to exceed Volcán Viejo in elevation. The Volcán Arrau dome complex was constructed SE of Volcán Nuevo between 1973 and 1986 and eventually exceeded its height.

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)