Report on Gede-Pangrango (Indonesia) — May 1991

Bulletin of the Global Volcanism Network, vol. 16, no. 5 (May 1991)
Managing Editor: Lindsay McClelland.

Gede-Pangrango (Indonesia) Brief earthquake 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, 16:5. Smithsonian Institution.

Volcano Profile |  Complete Bulletin



6.77°S, 106.965°E; summit elev. 3008 m

All times are local (unless otherwise noted)

Three shocks were felt (intensities I-III) on 30 April. Seismicity later returned to normal levels (10-15 events/day) during the second week of May (table 1).

Table 1. Number of earthquakes at Gede, May 1991. Courtesy of VSI.

Dates Deep Volcanic (VT) Shallow Volcanic Tectonic
01-04 May 1991 22 51 47
05-11 May 1991 197 635 9
12-18 May 1991 8 16 20
19-25 May 1991 23 8 9
26-31 May 1991 9 8 13

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.