Report on Chaiten (Chile) — 17 March-23 March 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 March-23 March 2010
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2010. Report on Chaiten (Chile). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 17 March-23 March 2010. Smithsonian Institution and US Geological Survey.
42.833°S, 72.646°W; summit elev. 1122 m
All times are local (unless otherwise noted)
On 17 March SERNAGEOMIN reported that, during the previous few weeks, growth of Chaitén's lava-dome complex was concentrated in the W part. Gas-and-ash plumes, seen through the video camera located on the rim of the caldera, rose at most 1 km from the central area of the domes. Seismic activity persisted at a low level. The Alert Level remained at Red.
Geologic Background. Chaitén is a small, glacier-free caldera with a compound Holocene lava dome located 10 km NE of the town of Chaitén on the Gulf of Corcovado. Early work had identified only a single explosive eruption during the early Holocene prior to the major 2008 eruption, but later work has identified multiple explosive eruptions throughout the Holocene. 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 prehistorical 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 historical eruption, beginning in 2008, produced major rhyolitic explosive activity and growth of a lava dome that filled much of the caldera.