Puyehue-Cordon Caulle volcano (Chile) - Smithsonian / USGS Weekly Volcanic Activity Report for 17 August-23 August 2011 (Continuing Activity)

During 16-23 August, OVDAS-SERNAGEOMIN reported that seismic activity indicated the eruption from the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, continued at a low level. Cloudy weather mostly prevented satellite and camera observations of the eruption during 16-17 August, however a mostly white plume was observed by an area camera rising 2 km above the crater on 16 August. A plume that was sometimes gray rose 2.5 km above the crater on 18 August.
A plume observed in satellite imagery that same day drifted 200 km NW. A period of harmonic tremor that lasted about 25 minutes may have indicated lava emission. Incandescence was observed at night during 18-19 August.

On 19 August a camera recorded a mostly white plume that rose 2 km above the crater. Satellite imagery showed a plume drifting 270 km NW. During an overflight, conducted by ONEMI in collaboration with the Air Force, scientists observed a white plume rising 1.4 km that was dark gray for the first few meters above the vent.
Solidified lava filled up a depression around Cordón Caulle; no active lava flows were noted. On 20 August a plume that was mostly white rose 2.5 km above the crater. Two explosive events caused the plume to rise 4 km and contain a higher concentration of ash.
Satellite imagery showed a plume drifting 200 km WNW on 20 August, and 500 km SE and NW on 21 August. A white plume that rose 2 km above the crater was observed on 22 August. Satellite imagery showed a very diffuse plume drifting E.
The Alert Level remained at Red.

Source: Servicio Nacional de Geología y Minería (SERNAGEOMIN)
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From: Global Volcanism Program, 2011. Report on Puyehue-Cordon Caulle. In: Mayberry, G (ed.), Weekly Volcanic Activity Report 17 August-23 August 2011. Smithsonian Institution and US Geological Survey.