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Report on Semeru (Indonesia) — December 2003

Bulletin of the Global Volcanism Network, vol. 28, no. 12 (December 2003)
Managing Editor: Richard Wunderman.

Semeru (Indonesia) November volcanism includes 70-90 explosions per day

Please cite this report as:

Global Volcanism Program, 2003. Report on Semeru (Indonesia). In: Wunderman, R. (ed.), Bulletin of the Global Volcanism Network, 28:12. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN200312-263300.

Volcano Profile |  Complete Bulletin


Semeru

Indonesia

8.108°S, 112.922°E; summit elev. 3657 m

All times are local (unless otherwise noted)


Volcanic activity at Semeru continued at a high level over the period 27 October-30 November, with a white-grey ash plume 300-600 m above the crater. A summary of seismicity (table 15) shows a ~ 20 percent reduction in the number of explosions compared to the previous four weekly intervals (BGVN 28:10). Semeru's hazard status remained at alert level 2 (on a scale of 1-4).

Table 15. Seismicity recorded at Semeru, 27 October-30 November. Courtesy of VSI.

Dates Volcanic A Tremor Tectonic Explosion Avalanche
27 Oct-02 Nov 2003 1 -- -- -- 2
03 Nov-09 Nov 2003 22 15 11 41 8
10 Nov-16 Nov 2003 4 13 12 3 7
17 Nov-23 Nov 2003 565 585 524 596 568
24 Nov-30 Nov 2003 11 17 14 15 7

Geologic Background. Semeru, the highest volcano on Java, and one of its most active, lies at the southern end of a volcanic massif extending north to the Tengger caldera. The steep-sided volcano, also referred to as Mahameru (Great Mountain), rises above coastal plains to the south. Gunung Semeru was constructed south of the overlapping Ajek-ajek and Jambangan calderas. A line of lake-filled maars was constructed along a N-S trend cutting through the summit, and cinder cones and lava domes occupy the eastern and NE flanks. Summit topography is complicated by the shifting of craters from NW to SE. Frequent 19th and 20th century eruptions were dominated by small-to-moderate explosions from the summit crater, with occasional lava flows and larger explosive eruptions accompanied by pyroclastic flows that have reached the lower flanks of the volcano.

Information Contacts: Dali Ahmad, Hetty Triastuty, Nia Haerani, and Suswati, Vulcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/).