Report on Slamet (Indonesia) — 22 April-28 April 2009
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 22 April-28 April 2009
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2009. Report on Slamet (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 22 April-28 April 2009. Smithsonian Institution and US Geological Survey.
7.242°S, 109.208°E; summit elev. 3428 m
All times are local (unless otherwise noted)
CVGHM reported that seismicity from Slamet increased during 19-23 April. Diffuse white plumes rose about 50 m above the crater on 20 April. During 21-23 April, white and white-to-brownish plumes rose 50-800 m above the crater. On 23 April, the Alert Level was raised to 3 (on a scale of 1-4); people were advised not to climb the summit. According to a news article, a CVGHM volcanologist stated that lava was ejected 600 m high and ash bursts up to 112 times within a 6-hour period were detected.
Geologic Background. Slamet, Java's second highest volcano at 3428 m and one of its most active, has a cluster of about three dozen cinder cones on its lower SE-NE flanks and a single cinder cone on the western flank. It is composed of two overlapping edifices, an older basaltic-andesite to andesitic volcano on the west and a younger basaltic to basaltic-andesite one on the east. Gunung Malang II cinder cone on the upper E flank on the younger edifice fed a lava flow that extends 6 km E. Four craters occur at the summit of Gunung Slamet, with activity migrating to the SW over time. Historical eruptions, recorded since the 18th century, have originated from a 150-m-deep, 450-m-wide, steep-walled crater at the western part of the summit and have consisted of explosive eruptions generally lasting a few days to a few weeks.