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. Photo by Jack Lockwood, U.S. Geological Survey, September 6, 1982.
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. Photograph by Robert Koyanagi, U.S. Geological Survey, July 28, 1979.
Rockfall from the collapse of a lava dome. Photo by Jack Lockwood, U.S. Geological Survey, September 8, 1982.
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. Photo by Jack Lockwood, U.S. Geological Survey, October 17, 1982.
Pyroclastic flow deposit on Merapi. Photo by Jack Lockwood, U.S. Geological Survey, November 2, 1982.
Kadong school is in the lower left of this photo. Barriers (just left of the stream valley) have protected the school fromlahars. 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. Photo by Jack Lockwood, U.S. Geological Survey, September 26, 1982.
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.
Sources of Information:
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.