Report on Llaima (Chile) — 23 May-29 May 2007
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 23 May-29 May 2007
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2007. Report on Llaima (Chile). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 23 May-29 May 2007. Smithsonian Institution and US Geological Survey.
38.692°S, 71.729°W; summit elev. 3125 m
All times are local (unless otherwise noted)
Based on a Significant Meteorological Information (SIGMET) advisory and satellite image observations, the Buenos Aires VAAC reported that ash plumes from Llaima rose to altitudes of 3-4.3 km (10,000-14,000 ft) a.s.l. on 26 May. The plumes were visible on satellite imagery drifting E. On 28 May, a pilot reported that an ash plume rose to 5.5-6.7 km (18,000-22,000 ft) a.s.l. and drifted E.
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.