Report on Merapi (Indonesia) — 14 June-20 June 2006
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 June-20 June 2006
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2006. Report on Merapi (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 14 June-20 June 2006. Smithsonian Institution and US Geological Survey.
7.54°S, 110.446°E; summit elev. 2910 m
All times are local (unless otherwise noted)
Gas plumes were emitted from Merapi on 14 and 15 June and reached a maximum height of 900 m above the summit (12,500 ft a.s.l.). On 14 June, a dome-collapse event, lasting approximately 3.5 hours, produced pyroclastic flows that reached a maximum distance of 7 km SE along the Gendol River. Two people assisting with evacuation efforts were trapped an underground shelter in Kaliadem village and died, the first fatalities of the current eruption. On 15 June, pyroclastic flows reached a maximum distance of 4.5 km SE along the Gendol River. According to news reports, pyroclastic flows continued during 16-19 June as a new dome grew. On 19 June, water shortages were reported. The Alert Level remained at 4, the highest level.
Geologic Background. Merapi, one of Indonesia's most active volcanoes, lies in one of the world's most densely populated areas and dominates the landscape immediately north of the major city of Yogyakarta. It is the youngest and southernmost of a volcanic chain extending NNW to Ungaran volcano. Growth of Old Merapi during the Pleistocene ended with major edifice collapse perhaps about 2000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequently growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent eruptive activity, began SW of the earlier collapse scarp. Pyroclastic flows and lahars accompanying growth and collapse of the steep-sided active summit lava dome have devastated cultivated lands on the western-to-southern flanks and caused many fatalities during historical time.