Merapi is a stratovolcano in central Java. Merapi has had 68 historic eruption since 1548. The current eruption began in 1987. Because of Merapi's violent past and its close proximity to Yogyakarta it was designated a Decade Volcano and is the target of increased research efforts.
Merapi is a stratovolcano with an active summit lava dome. It is located ~30 km immediately north of Yogyakarta, a city with a population of 500,000. Merapi has the unfortunate distinction of producing more nuee ardentes than any other volcano on Earth. The nuee ardentes result from collapse of the lava dome at the summit. Of the 67 historic eruptions 32 have had nuee ardentes associated with them. Eleven of these eruptions resulted in fatalities. Merapi is closely monitored by the Volcanological Survey of Indonesia. Shortly before this photograph was taken Merapi was generating up to 40 nuee ardentes per day.
Rockfall from the collapse of a lava dome.
Lava dome at the summit of Merapi. During 1982, the lava dome was growing about 80,000-100,000 cubic meters per month. The dome collapsed in late November, creating nuee ardentes.
Pyroclastic flow deposit on Merapi.
Kadong school is in the lower left of this photo. Barriers (just left of the stream valley) have protected the school from lahars. In 1979, heavy rainfall mobilized old lahar deposits to create landslides that travelled as far as 12 miles (20 km) downslope. Eighty people were killed.
In late November of 1994, collapse of a lava dome at Merapi generated pyroclastic flows and surges that travelled as far as 5 miles (7.5 km) from the summit. The flows and surges killed 43 people. The plume associated with the dome collapse rose 6 miles (10 km) above the volcano. Over 6,000 people were evacuated. The eruption also started fires.
More information on Merapi Hazards
Sources of Information:
Andreastuti, S.D., Alloway, B.V., and Smith, I.E.M., 1997, A detailed tephrostratigraphy at Merapi volcano, central Java: Implication for eeruption prediction and hazard assessment, in Program and Abstract, 2nd Merapi Decade Volcano International Workshop, Yogyakarta, VSI-UNESCO, p. 26.
Purbawinata, M.A., Ratdomopurbo, A., Sinulingga, I.K., Sumarti, S., Suharno, 1996, Merapi volcano a guide book: Volcanological Survey of Indonesia, Bandung, 64 p.
Suryo, I. and Clarke, M.C.G., 1985, The occurrence and mitigation of volcanic hazards in Indonesia as exemplified at the Mount Merapi, Mount Kelut, and Mount Galunggung volcanoes: Q.J. Eng. Geol. London, v. 185, p. 79-98.
Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.
Smithsonian Institution's Global Volcanism Network, 1995, Summary of Recent Activity: Bulletin of Volcanology, v. 57, p. 73-75.