Report on Papandayan (Indonesia) — 24 August-30 August 2011
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 24 August-30 August 2011
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2011. Report on Papandayan (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 24 August-30 August 2011. Smithsonian Institution and US Geological Survey.
7.32°S, 107.73°E; summit elev. 2665 m
All times are local (unless otherwise noted)
On 26 August CVGHM reported that Papandayan showed minor to no changes in recent seismicity, deformation, geochemistry, and visual observations; therefore the Alert Level remained at 3 (on a scale of 1-4). Seismicity remained high, but stable, and was dominated by shallow volcanic earthquakes. Deformation measurements showed no change, and water temperatures in multiple fumarolic areas and lakes remained relatively unchanged. Sulfur dioxide gas emissions decreased from 8 tons per day on 12 August to 6 tons per day on 23 August. Carbon dioxide in the soil at a 1 m depth in multiple areas did not increase. Visitors and residents were advised not to venture within 2 km of the active crater.
Geologic Background. Papandayan is a complex stratovolcano with four large summit craters, the youngest of which was breached to the NE by collapse during a brief eruption in 1772 and contains active fumarole fields. The broad 1.1-km-wide, flat-floored Alun-Alun crater truncates the summit of Papandayan, and Gunung Puntang to the north gives a twin-peaked appearance. Several episodes of collapse have created an irregular profile and produced debris avalanches that have impacted lowland areas. A sulfur-encrusted fumarole field occupies historically active Kawah Mas ("Golden Crater"). After its first historical eruption in 1772, in which collapse of the NE flank produced a catastrophic debris avalanche that destroyed 40 villages and killed nearly 3000 people, only small phreatic eruptions had occurred prior to an explosive eruption that began in November 2002.