POVI reported that four ash emissions at Villarrica were visible in webcam images on 16 December. SERNAGEOMIN stated that two ash pulses were associated with long-period (LP) events at 1146 and 1156 that same day; the first ash emission rose 160 m above the crater rim and drifted NW while the second rose 280 m and drifted 500 m NE. At 1716 on 17 December an ash emission associated with an LP event rose 720 m and drifted ESE. 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.

Geological Summary. The glacier-covered Villarrica stratovolcano, in the northern Lakes District of central Chile, is ~15 km south of the city of Pucon. A 2-km-wide caldera that formed about 3,500 years ago is located at the base of the presently active, dominantly basaltic to basaltic-andesite cone at the NW margin of a 6-km-wide Pleistocene caldera. More than 30 scoria cones and fissure vents are present on 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. Eruptions documented since 1558 CE 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.

Sources: Servicio Nacional de Geología y Minería (SERNAGEOMIN), Proyecto Observación Villarrica Internet (POVI), Oficina Nacional de Emergencia-Ministerio del Interior (ONEMI)