SERNAGEOMIN reported that clouds obscured camera views of Chaitén's eruption plume during most of 26-29 August. Glimpses utilizing the web camera revealed that continuous ash plumes rose to an altitude of 1.5 km (4,900 ft) a.s.l. and drifted SW. They also reported that seismicity had increased slightly during the previous few days.

Based on web camera views and analysis of satellite imagery, the Buenos Aires VAAC reported that during 27-29 August ash plumes rose to altitudes of 1.8-3 km (6,000-10,000 ft) a.s.l. and drifted SE.

Geological Summary. Chaitén is a small caldera (~3 km in diameter) located 10 km NE of the town of Chaitén on the Gulf of Corcovado. Multiple explosive eruptions throughout the Holocene have been identified. A rhyolitic obsidian lava dome occupies much of the caldera floor. Obsidian cobbles from this dome found in the Blanco River are the source of artifacts from archaeological sites along the Pacific coast as far as 400 km from the volcano to the N and S. The caldera is breached on the SW side by a river that drains to the bay of Chaitén. The first recorded eruption, beginning in 2008, produced major rhyolitic explosive activity and building a new dome and tephra cone on the older rhyolite dome.

Sources: Buenos Aires Volcanic Ash Advisory Center (VAAC), Servicio Nacional de Geología y Minería (SERNAGEOMIN)