Report on Merapi (Indonesia) — March 1977
Natural Science Event Bulletin, vol. 2, no. 3 (March 1977)
Managing Editor: David Squires.
Merapi (Indonesia) Lava dome growth continues; frequent avalanches
Please cite this report as:
Global Volcanism Program, 1977. Report on Merapi (Indonesia) (Squires, D., ed.). Natural Science Event Bulletin, 2:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.NSEB197703-263250.
7.54°S, 110.446°E; summit elev. 2910 m
All times are local (unless otherwise noted)
The new lava dome, had increased in volume from about 2 x 103 m3 in June, 1976 to about 2.5 x l06 m3 in late February, 1977. Avalanches continued to occur at intervals of 15 minutes or more; sometimes, but not every day, nuées ardentes accompanied the avalanches, especially after a heavy rainfall.
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: J. Matahelumual, Volcanology Division, GSI; D. Shackelford, Villa Park, CA.