 Mount Merapi, Gunung Merapi (literally Mountain of Fire) in Indonesian language, is a conical volcano located on the border between Central Java and Yogyakarta, Indonesia. It is the most active volcano in Indonesia and has erupted regularly since 1548. It is very close to the city of Yogyakarta, and thousands of people live on the flanks of the volcano, with villages as high as 1700 m above sea level.
Although smoke can be seen emerging from the mountain top at least 300 days a year, several eruptions have caused fatalities. Hot gas from a large explosion killed 64 people on November 22 in 1994, mostly in the town of Muntilan, west of the volcano. Another large eruption occurred in 2006, shortly before the Yogyakarta earthquake. In light of the hazards that Merapi poses to populated areas, it has been designated as one of the Decade Volcanoes.
Merapi history
Merapi is the youngest in a group of volcanoes in southern Java. It is
situated at a subduction zone, where the Indo-Australian Plate is
sliding beneath the Eurasian Plate. It is one of at least 129 active
volcanoes in Indonesia, part of the Pacific Ring of Fire – a section of
fault lines stretching from the Western Hemisphere through Japan and
South East Asia.
Stratigraphic analysis reveals that eruptions in the Merapi area began
about 400,000 years ago, and from then until about 10,000 years ago,
eruptions were typically effusive, and the outflowing lava emitted was
basaltic. Since then, eruptions have become more explosive, with
viscous andesitic lavas often generating lava domes. Dome collapse has
often generated pyroclastic flows, and larger explosions, which have
resulted in eruption columns, have also generated pyroclastic flows
through column collapse.
There has been no late eruption. Typically, small eruptions occur every
two to three years, and larger ones every 10-15 years or so. Notable
eruptions, often causing many deaths, have occurred in 1006, 1786,
1822, 1872 (the most violent eruption in recent history), and 1930—when
thirteen villages were destroyed and 1400 people killed by pyroclastic
flows.
A very large eruption in 1006 is claimed to have covered all of central
Java with ash. The volcanic devastation is claimed to have led to the
collapse of the Hindu Kingdom of Mataram, however there is insufficient
evidence from that era for this to be substantiated.
Merapi continues hold particular significance for the Javanese: it is
one of four places where officials from the royal palaces of Yogyakarta
and Solo make annual offerings to placate the ancient Javanese spirits.
2006 Eruption
In April 2006, increased seismicity at more regular intervals and a
detected bulge in the volcano's cone indicated that fresh eruptions
were imminent. Authorities put the volcano's neighboring villages on
high alert and local residents prepared for a likely evacuation. On
April 19 smoke from the crater reached a height of 400 meters, compared
to 75 metres the previous day. On April 23, after nine surface tremors
and some 156 multifaced quakes signalled movements of magma, some 600
elderly and infant residents of the slopes were evacuated.
By early May, active lava flows had begun. On May 11, with lava flow
beginning to be constant, some 17,000 people were ordered to be
evacuated from the area and on May 13, Indonesian authorities raised
the alert status to the highest level, ordering the immediate
evacuation of all residents on the mountain.
Many villagers
defied the dangers posed by the volcano and returned to their villages,
fearing that their livestock and crops would be vulnerable to theft.
Activity calmed by the middle of May.
On May 27, a 6.2 magnitude
earthquake struck roughly 30 miles southwest of Merapi, killing at
least 5,000 and leaving at least 200,000 people homeless in the
Yogyakarta region, heightening fears that Merapi will "blow". The quake
did not appear to be a long-period oscillation, a seismic disturbance
class that is increasingly associated with major volcanic eruptions. A
further 11,000 villagers were evacuated on June 6 as lava and
superheated clouds of gas poured repeatedly down its upper slopes. The pyroclastic flows are known locally as "wedhus gembel" (Javanese for "shaggy goat").
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