Report on Merapi (Indonesia) — November 1986
Scientific Event Alert Network Bulletin, vol. 11, no. 11 (November 1986)
Managing Editor: Lindsay McClelland.
Merapi (Indonesia) Summit lava dome growth
Please cite this report as:
Global Volcanism Program, 1986. Report on Merapi (Indonesia) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 11:11. Smithsonian Institution.
7.54°S, 110.446°E; summit elev. 2910 m
All times are local (unless otherwise noted)
Renewed growth of the summit lava dome began in early October and continued into November. As of mid-Nov, the lava dome volume was 3 x 106 m3. Several hundred rockfalls/day have been occurring since mid-Oct.
Geological Summary. 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 2,000 years ago, leaving a large arcuate scarp cutting the eroded older Batulawang volcano. Subsequent growth of the steep-sided Young Merapi edifice, its upper part unvegetated due to frequent 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.
Information Contacts: VSI; ANS.