Report on Villarrica (Chile) — 14 October-20 October 2020
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 October-20 October 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, 14 October-20 October 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 that explosions at Villarrica were recorded at 0534 and 0804 on 15 October and were each associated with long-period seismicity. The first explosion ejected incandescent material above the crater rim and deposited tephra on the E flank as far as 3 km. The second explosion ejected tephra 450 m. An explosion and long-period event were recorded at 1722 on 20 October; an ash plume rose 240 m above the vent and drifted S. POVI noted that the vent was 5-6 m in diameter at a depth of 150 m below the crater rim. The Alert Level remained 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 the exclusion zone for the public 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.