Report on Slamet (Indonesia) — 10 September-16 September 2014
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 10 September-16 September 2014
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2014. Report on Slamet (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 10 September-16 September 2014. Smithsonian Institution and US Geological Survey.
7.242°S, 109.208°E; summit elev. 3428 m
All times are local (unless otherwise noted)
PVMBG reported explosive activity from Slamet during 4-12 September. During the past week, activity peaked with incandescent explosions; rumbling sounds were heard by scientists at the Slamet observation post. On 11 September the largest ash plume was observed (200-1,500 m above the summit) and incandescent plumes reached 400 m above the summit. Seismicity was dominated by emissions and explosion signals. Deformation data indicated that relatively little pressure was accumulating due to magma movement. PVMBG maintained the Alert Level 3 (on a scale of 1-4).
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.