Report on Villarrica (Chile) — October 1983
Scientific Event Alert Network Bulletin, vol. 8, no. 10 (October 1983)
Managing Editor: Lindsay McClelland..
Villarrica (Chile) Continuous explosions emit tephra; pyroclastic flows; summit glow suggests lava fountaining
Please cite this report as:
Global Volcanism Program, 1983. Report on Villarrica (Chile). In: McClelland, L. (ed.), Scientific Event Alert Network Bulletin, 8:10. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198310-357120.
39.42°S, 71.93°W; summit elev. 2847 m
All times are local (unless otherwise noted)
"Forest guards in the Villarrica National Park reported that the volcano entered into a remarkable eruptive stage on 14 October, after a long period of moderate activity. Continuous explosions with tephra emissions and some black pyroclastic flows over the ice-covered slopes have been observed. By night, a red glow over the summit indicates that a lava fountain is filling the crater. Since the big lava and pyroclastic eruptions of October-December 1971, active fumaroles have been present in the main crater."
Further Reference. Muñoz, M., 1984, Probabilidad de erupción en el Volcán Villarrica en los próximos años: Tralka, v. 2, no. 3, p. 323-325.
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.