Report on Villarrica (Chile) — 22 January-28 January 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 22 January-28 January 2020
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2020. Report on Villarrica (Chile). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 22 January-28 January 2020. Smithsonian Institution and US Geological Survey.
39.42°S, 71.93°W; summit elev. 2847 m
All times are local (unless otherwise noted)
SERNAGEOMIN reported low levels of activity at Villarrica during 1-15 January, characterized by whitish gas plumes rising 250 m above the crater rim and nighttime crater incandescence observed during periods of clear weather. Sulfur dioxide gas emissions averaged around 349 tons per day, peaking at 468 tons per day on 3 January. Low-energy thermal anomalies were identified on 11, 13, and 14 January. POVI reported that lava fountaining from 4-5-m-diameter vents was visible during 18-20 and 22 January. Low levels of activity and minor explosions were noted on 27 January. SERNAGEOMIN maintained the Alert Level at Yellow, the second lowest level on a four-color scale. ONEMI maintained an Alert Level Yellow (the middle level on a three-color scale) for the municipalities of Villarrica, Pucón (16 km N), Curarrehue, and the commune of Panguipulli, and changed the exclusion zone for the public to a radius of 500 m around the crater.
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.