Report on Llaima (Chile) — 13 February-19 February 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 13 February-19 February 2008
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2008. Report on Llaima (Chile). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 13 February-19 February 2008. Smithsonian Institution and US Geological Survey.
38.692°S, 71.729°W; summit elev. 3125 m
All times are local (unless otherwise noted)
SERNAGEOMIN reported that explosions in the main crater of Llaima propelled incandescent material 200-500 m in the air during 8-13 February. Explosions occasionally alternated between N and S cones in the main crater. On 9 February, the Calbuco River was about 1 m higher than the normal level, likely due to melt water from the lava and glacier interaction. On 10 February, Strombolian eruptions from the main crater were observed during an overflight. The lava flows on the W flank were 2.5 km long and made channels in the ice tens of meters deep. Although visual observations were limited due to cloud cover, sulfur dioxide and steam plumes from lava interacting with ice during 10-14 and 17 February rose to altitudes of 4.1-6.1 km (13,500-20,000 ft) a.s.l. Plumes drifted SE on 11 February. Lava flows were 3 km long on 11 February. On 13 February, incandescence at the summit was noted.
Geologic Background. Llaima, one of Chile's largest and most active volcanoes, contains two main historically active craters, one at the summit and the other, Pichillaima, to the SE. The massive, dominantly basaltic-to-andesitic, stratovolcano has a volume of 400 km3. A Holocene edifice built primarily of accumulated lava flows was constructed over an 8-km-wide caldera that formed about 13,200 years ago, following the eruption of the 24 km3 Curacautín Ignimbrite. More than 40 scoria cones dot the volcano's flanks. Following the end of an explosive stage about 7200 years ago, construction of the present edifice began, characterized by Strombolian, Hawaiian, and infrequent subplinian eruptions. Frequent moderate explosive eruptions with occasional lava flows have been recorded since the 17th century.