Report on Villarrica (Chile) — 6 September-12 September 2017
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
6 September-12 September 2017
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2017. Report on Villarrica (Chile). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 6 September-12 September 2017. Smithsonian Institution and US Geological Survey.
39.42°S, 71.93°W; summit elev. 2847 m
All times are local (unless otherwise noted)
In a summary of August activity at Villarrica, Proyecto Observación Villarrica Internet (POVI) reported that the crater was only partially visible on nine days. On 2 September a small incandescent vent at the bottom of the crater was visible. An explosion at 0924 on 30 August ejected gas and ash that drifted E due to strong winds; observers noted ash and lapilli deposits on the snow during a field visit later that day.
Geological Summary. 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.