Merapi volcano (summit altitude 2968 m above sea level, per 2006) is a volcano in the central part of Java Island and is one of the most active volcanoes in Indonesia. Slopes of the south side are in the administrative district of Sleman, Yogyakarta Special Region, and the rest are in the region of Central Java province, namely Magelang district on the west side, Boyolali district in the north and east, and Klaten district in the southeast. The forest area around the peak to be Mount Merapi National Park area since 2004.
The mountain is very dangerous because, according to modern records have eruption (peak activity) every two to five years and is surrounded by very dense settlement. Since the year 1548, this mountain has erupted 68 times as much. [Citation needed] The city of Yogyakarta is the nearest big city, located about 27 km from the peak, and there are still villages in the slope to a height of 1700 m and only 4 km away from the summit. Because of this importance, Merapi became one of sixteen volcanoes of the world are included in the Decade Volcano Project
GeologyLithography south side of Mount Merapi in 1836, published in a book written by Junghuhn.
Mount Merapi is the youngest mountain in the volcanic chain that leads to the south of Mount Ungaran. The mountain is located in the subduction zone of the Indo-Australian Plate is moving down the Eurasian Plate. Current peak is not overgrown vegetation because of high volcanic activity. This peak grows in the southwest side of the peak of Mount Batulawang older. [2]
The formation of Mount Merapi has been studied and published since 1989 and so on. [3] Berthomier, a French scholar, divide into four stages of development Merapi. [4] The first stage is Pre-Merapi (up to 400,000 years ago), that is a part of Mount Aunt can still be seen on the eastern side of the peak of Merapi. Old Merapi stage occurs when Merapi began to form but not yet conical (60000-8000 years ago). The remains of this stage is Turgo Hill and Hill Plawangan in the south, which is formed from basaltic lava. Next is the Middle Merapi (8000 - 2000 years ago), characterized by the formation of high peaks, like Mount Gajahmungkur and Batulawang, which is composed of andesite lava. The process of formation in this period is characterized by lava flows, brecciation of lava and hot clouds. Merapi activity has to be effusive eruption (melt) and explosive. Also estimated that an explosive eruption with debris material to the west that left the horseshoe morphology with length 7 km, 1-2 km wide with a few hills on the western slope. Pasarbubar or Pasarbubrah crater formed is estimated at this time. Merapi peak now, peak Anyar, a new beginning to form around 2000 years ago. In its development, is known to occur several times explosive eruption with VEI 4 based on the observation tefra layer.
Characteristics of eruptions since 1953 is the insistence of lava into the summit crater accompanied by periodic lava dome collapse and pyroclastic formation (nuee ardente) that can slide on the slopes or vertically upward. The eruption of Merapi type is generally not a sound but the hiss of explosions. Dome of the existing peak until 2010 was the result of an ongoing process since the gas explosion of 1969. [2]
In a cooperative project with the Indonesian Directorate of Volcanology (PVMBG), geologist Earth Research Centre in Potsdam, Germany, detected a giant space below Merapi contain materials such as mud that are "significantly impede the vibration waves of an earthquake." Scientists estimate that the magma material. [5] [6].The peak of Merapi in 1930.
Small eruptions occur every 2-3 years, and the larger about 10-15 years. Merapi eruptions recorded a big impact in the years 1006, 1786, 1822, 1872, and 1930. Large eruption in 1006 made the whole central part of Java island shrouded in ash, based on observations of volcanic ash heap. [Citation needed] Dutch geologist, van Bemmelen, theorized that the eruption caused the central Medang Kingdom (Ancient Mataram) should move to East Java. The eruption in 1872 is considered as the most powerful eruption in modern geological record with VEI scale reaches 3 to 4. The latest eruption, 2010, is estimated to also have the power close to or equal. The eruption in 1930, which destroyed three dozen villages and killed 1400 people, is the biggest victims of the eruption with the record until now. [Citation needed]
November 1994 eruption caused hot clouds glide down to reach some villages and claimed 60 human lives. July 19, 1998 eruption is big enough but it pointed up so it does not take casualties. Note the last eruption of this mountain was in 2001-2003 in the form of high activity are ongoing. In 2006 Mount Merapi high-return activities and had claimed two lives of volunteers in the region because of a hack Kaliadem hot clouds. The series of eruptions in October and November 2010 were evaluated as the largest during the last 100 years, threatens 32 villages [7] and claimed lives of more than 100 people (the numbers are still subject to change), although the observation of Merapi has been very intensive and management of refugee camps have been functioning relatively good. [citation needed] The eruption was also observed as a deviation because the explosive sound accompanied the explosions and the roar is heard up to a distance of 20-30 km.
The mountain is monitored non-stop by the Centre for Observation of Mount Merapi in Yogyakarta, assisted by various geophysical telemetry instruments around the mountain peak and a number of visual observation post and seismic recorder in Ngepos, Srumbung, Babadan, and Kaliurang
