Report on Galunggung (Indonesia) — 8 February-14 February 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 8 February-14 February 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Galunggung (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 8 February-14 February 2012. Smithsonian Institution and US Geological Survey.
7.25°S, 108.058°E; summit elev. 2168 m
All times are local (unless otherwise noted)
On 13 February, CVGHM reported that from September 2011 to 8 February 2012 discolorations in the crater lake water at Galunggung were observed. In addition, a sudden increase in water temperature was measured, from 27 degrees Celsius on 5 February to 40 degrees on 8 February. Based on seismic data and crater lake observations, CVGHM raised the Alert Level from 1 to 2 (on a scale of 1-4) on 12 February and recommended staying at least 500 m away from the lake shore.
Geologic Background. The forested slopes Galunggung in western Java are cut by a large horseshoe-shaped caldera breached to the SE that has served to channel the products of recent eruptions in that direction. The "Ten Thousand Hills of Tasikmalaya" dotting the plain below the volcano are debris-avalanche hummocks from the collapse that formed the breached caldera about 4200 years ago. Although historical eruptions, restricted to the central vent near the caldera headwall, have been infrequent, they have caused much devastation. The first historical eruption in 1822 produced pyroclastic flows and lahars that killed over 4000 people. More recently, a strong explosive eruption during 1982-1983 caused severe economic disruption to populated areas near the volcano.