Merapi
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.