Report on Chaiten (Chile) — 6 January-12 January 2010
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 6 January-12 January 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, 6 January-12 January 2010. Smithsonian Institution and US Geological Survey.
42.833°S, 72.646°W; summit elev. 1122 m
All times are local (unless otherwise noted)
SERNAGEOMIN reported that during 16 December 2009-4 January 2010 steam-and-gas plumes from Chaitén's lava-dome complex seen on the web camera during periods of clear weather rose 1.5 km above the lava domes. Seismicity, along with occasional block-and-ash flows, indicated that the lava domes continued to grow. Based on web camera views and analyses of satellite imagery, the Buenos Aires VAAC reported that on 6 January a plume drifted 50 km ENE at an altitude of 2.1 km (7,000 ft) a.s.l. The next day an ash plume drifted SE and E at the same altitude.
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.