Report on Merapi (Indonesia) — July 1979
Scientific Event Alert Network Bulletin, vol. 4, no. 7 (July 1979)
Managing Editor: David Squires.
Merapi (Indonesia) Hot avalanches decline; dome growth continues
Please cite this report as:
Global Volcanism Program, 1979. Report on Merapi (Indonesia). In: Squires, D. (ed.), Scientific Event Alert Network Bulletin, 4:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197907-263250.
7.54°S, 110.446°E; summit elev. 2910 m
All times are local (unless otherwise noted)
Newspaper reports state that hot avalanches from the lava dome decreased in frequency during May, after as many as 40/day had occurred in April. The May avalanches traveled as much as 1.75 km. Growth continued at the new dome, which first appeared in January 1979 and now covers the remnants of the 1973 and 1978 domes.
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.
Information Contacts: Kompas, Jakarta; M. Krafft, Cernay.