Report on Galunggung (Indonesia) — November 1982
Scientific Event Alert Network Bulletin, vol. 7, no. 11 (November 1982)
Managing Editor: Lindsay McClelland.
Galunggung (Indonesia) Explosion and lahars
Please cite this report as:
Global Volcanism Program, 1982. Report on Galunggung (Indonesia) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 7:11. Smithsonian Institution.
7.25°S, 108.058°E; summit elev. 2168 m
All times are local (unless otherwise noted)
Press sources reported that an explosion on 3 December ejected ash and incandescent material. Strong winds blew fine ash to Garut. Within an hour, lahars were flowing down two river valleys. Heavy clouds that cover Java for much of the day during the rainy season prevented satellite observation of the eruption cloud. No explosions had been reported since 4 November and the 3 December explosion was said to follow "a period of relative calm."
Since the eruption began 5 April, ~ 40 x 106 m3 of tephra and mud have accumulated on the flanks of the volcano. Monsoon rains threaten to remobilize this material and form destructive lahars. In the primary danger zone, residents have been given 40,000 plastic bags, which are to be filled with sand and used as a protection against flooding. Authorities have warned residents of the city of Tasikmalaya of the danger of lahars.
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 4,200 years ago. Historical eruptions have been infrequent and restricted to the central vent near the caldera headwall, but have caused much devastation. The first historical eruption in 1822 produced pyroclastic flows and lahars that killed over 4,000 people. A strong explosive eruption during 1982-1983 caused severe economic disruption to nearby populated areas.
Information Contacts: D. Haller, NOAA; AFP; Sinar Harapan, Jakarta.