SERNAGEOMIN reported that a long-period earthquake recorded at 1643 on 2 September was accompanied by a minor ash plume that rose to 180 m above Villarrica’s summit crater rim and dispersed SE. According to the Buenos Aires VAAC, periods of continuous gas-and-ash emissions were visible in webcam images from 1830 on 2 September to 0110 on 3 September. POVI reported that the lava lake was active and during 3-4 September lava fountaining was visible for the first time since 26 March. Fountains captures in webcam images at 2133 on 3 September and 0054 on 4 September rose as high as 60 m above the crater rim and ejected material onto the upper W flank. The Volcanic Alert level remained at Yellow (the second highest on a four-level scale) according to SERNAGEOMIN and the public was warned to stay 500 m away from the crater. SENAPRED maintained the Alert Level at Yellow (the middle level on a three-color scale) for the communities of Villarrica, Pucón (16 km N), Curarrehue, and Panguipulli.

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), Sistema y Servicio Nacional de Prevención y Repuesta Ante Desastres (SENAPRED), Proyecto Observación Villarrica Internet (POVI), Buenos Aires Volcanic Ash Advisory Center (VAAC)