According to Projecto Observación Visual Volcán Villarrica (POVI), satellite images of Villarrica acquired on 10 and 26 November and 3 December revealed a progressively more intense thermal anomaly. Photographs on 9 December showed particulates suspended above the crater rim, and the next day a thin veneer of ash covered the NW edge of the crater rim. Detonations from the crater were heard during 10-12 December. On 13 December observers noted that the intense blasts of gas from the previous few days had removed some ash deposits from the inner crater wall leaving lighter colored streaks.

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.

Source: Proyecto Observación Villarrica Internet (POVI)