Report on Gede-Pangrango (Indonesia) — June 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 6 (June 1991)
Managing Editor: Lindsay McClelland.
Gede-Pangrango (Indonesia) Seismicity declines without eruption after April/May swarm
Please cite this report as:
Global Volcanism Program, 1991. Report on Gede-Pangrango (Indonesia). In: McClelland, L (ed.), Bulletin of the Global Volcanism Network, 16:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199106-263060.
6.77°S, 106.965°E; summit elev. 3008 m
All times are local (unless otherwise noted)
High seismicity associated with the 29 April-1 May swarm activity has continuously declined since late May (figure 1). An average of one volcanic earthquake/day was recorded in June, compared to 43/day in April and 5/day in May. No surface activity was observed.
Geologic Background. Gede volcano is one of the most prominent in western Java, forming a twin volcano with Pangrango volcano to the NW. The major cities of Cianjur, Sukabumi, and Bogor are situated below the volcanic complex to the E, S, and NW, respectively. Gunung Pangrango, constructed over the NE rim of a 3 x 5 km caldera, forms the high point of the complex at just over 3000 m elevation. Many lava flows are visible on the flanks of the younger Gunung Gede, including some that may have been erupted in historical time. The steep-walled summit crater has migrated about 1 km NNW over time. Two large debris-avalanche deposits on its flanks, one of which underlies the city of Cianjur, record previous large-scale collapses. Historical activity, recorded since the 16th century, typically consists of small explosive eruptions of short duration.
Information Contacts: W. Modjo, VSI.