Report on Llaima (Chile) — 17 September-23 September 2008
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 17 September-23 September 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, 17 September-23 September 2008. Smithsonian Institution and US Geological Survey.
38.692°S, 71.729°W; summit elev. 3125 m
All times are local (unless otherwise noted)
During an overflight of Llaima on 12 September, SERNAGEOMIN scientists observed diffuse gas-and-steam plumes emitted from the external edges of the nested craters in the main crater. During 13-22 September, observers in Melipeuco (about 17 km SSE) reported that sporadic gas-and-steam plumes emanated from the main crater. During an overflight on 21 September, steam emissions were noted from areas on the NE and W flanks. The Alert remained at Green, Level 2.
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.