Report on Villarrica (Chile) — September 1980
Scientific Event Alert Network Bulletin, vol. 5, no. 9 (September 1980)
Managing Editor: David Squires.
Villarrica (Chile) Ash eruptions and pyroclastic flow
Please cite this report as:
Global Volcanism Program, 1980. Report on Villarrica (Chile). In: Squires, D. (ed.), Scientific Event Alert Network Bulletin, 5:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198009-357120.
39.42°S, 71.93°W; summit elev. 2847 m
All times are local (unless otherwise noted)
After a long period of fumarolic activity, a series of explosions that began on 19 September at 2200 ejected ash from the main crater. The next morning, a long, dark-colored pyroclastic flow could be seen on the NW flank. On 24 September at 0800 fine ash was ejected briefly, covering Villarrica's snowy slopes.
Geologic Background. Glacier-clad Villarrica, one of Chile's most active volcanoes, rises above the lake and town of the same name. It is the westernmost of three large stratovolcanoes that trend perpendicular to the Andean chain. A 6-km-wide caldera formed during the late Pleistocene. A 2-km-wide caldera that formed about 3500 years ago is located at the base of the presently active, dominantly basaltic to basaltic-andesitic cone at the NW margin of the Pleistocene caldera. More than 30 scoria cones and fissure vents dot the flanks. Plinian eruptions and pyroclastic flows that have extended up to 20 km from the volcano were produced during the Holocene. Lava flows up to 18 km long have issued from summit and flank vents. Historical eruptions, documented since 1558, have consisted largely of mild-to-moderate explosive activity with occasional lava effusion. Glaciers cover 40 km2 of the volcano, and lahars have damaged towns on its flanks.
Information Contacts: H. Moreno R., Univ. de Chile, Santiago.