Report on Sundoro (Indonesia) — 28 March-3 April 2012
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 28 March-3 April 2012
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2012. Report on Sundoro (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 28 March-3 April 2012. Smithsonian Institution and US Geological Survey.
7.3°S, 109.992°E; summit elev. 3136 m
All times are local (unless otherwise noted)
CVGHM reported that seismicity at Sundoro continued to increase into January after the Alert Level was raised from 1 to 2 (on a scale of 1-4) on 5 December 2011. After the first week of January through 27 March the number of daily earthquakes significantly decreased. The Alert Level was lowered to 1 on 30 March.
Geologic Background. Gunung Sundoro, one Java's most symmetrical volcanoes, is separated by a 1400-m-high saddle from Sumbing volcano. Parasitic craters and cones, the largest of which is Kembang, occur on the NW-to-southern flanks, and all fed lava flows. A small lava dome occupies the summit crater, and numerous phreatic explosion vents were formed along radial fissure that cut the dome and extend across the crater rim. Lava flows extend in all directions from the summit crater. Deposits of a large prehistoric debris avalanche are located below the NE flank. Pyroclastic-flow deposits dated at 1720 years before present extend as far as 13 km from the summit. Historical eruptions typically have consisted of mild-to-moderate phreatic explosions, mostly from the summit crater. Flank vents were also active in 1882 and 1903.