Report on Marapi (Indonesia) — May 1999
Bulletin of the Global Volcanism Network, vol. 24, no. 5 (May 1999)
Managing Editor: Richard Wunderman
Marapi (Indonesia) Declining activity and weak ash emissions
Please cite this report as:
Global Volcanism Program, 1999. Report on Marapi (Indonesia). In: Wunderman, R (ed.), Bulletin of the Global Volcanism Network, 24:5. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.BGVN199905-261140.
0.381°S, 100.473°E; summit elev. 2891 m
All times are local (unless otherwise noted)
Activity of Marapi volcano was subdued during the period from late April to late May. From 27 April-3 May, only the emissions events increased (from 21 to 30) from the previous week; volcanic type-A, type-B, and tectonic events, along with eruptions, all decreased. During 4-17 May observed activity was limited to thin white-gray ash emissions that rose 100-400 m above the summit.
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: Volcanological Survey of Indonesia (VSI), Jalan Diponegoro No. 57, Bandung 40122, Indonesia (URL: http://www.vsi.esdm.go.id/).