Report on Marapi (Indonesia) — June 1987
Scientific Event Alert Network Bulletin, vol. 12, no. 6 (June 1987)
Managing Editor: Lindsay McClelland
Marapi (Indonesia) Small explosions; ashfall on two cities
Please cite this report as:
Global Volcanism Program, 1987. Report on Marapi (Indonesia). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 12:6. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.SEAN198706-261140.
0.381°S, 100.473°E; summit elev. 2891 m
All times are local (unless otherwise noted)
Small explosions occurred on 25 and 30 May, and 1, 5, 7, 9, 10, and 11 June, with column heights reaching 1 km above the summit. A light dusting of ash fell on Bukittinggi,  km NW [of the summit], and Padang,  km [SSW]. The previous activity at Marapi occurred 15 January.
Geologic Background. Gunung Marapi, not to be confused with the better-known Merapi volcano on Java, is Sumatra's most active volcano. This massive complex stratovolcano rises 2000 m above the Bukittinggi plain in the Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, with volcanism migrating to the west. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no lava flows outside the summit craters have been reported in historical time.
Information Contacts: VSI.