Mount Merapi
Merapi, July 2005
Elevation	2,914 metres (9,560 ft)
Location	Border of Central Java / Yogyakarta (Indonesia)
Coordinates	7°32′S 110°26′E / -7.533, 110.433Coordinates: 7°32′S 110°26′E / -7.533, 110.433
Type	Stratovolcano
Age of rock	400,000 years
Last eruption	2006
Translation	Mountain of Fire (Indonesian)

Mount Merapi, Gunung Merapi in Indonesian language, is a conical volcano located on the border between Central Java and Yogyakarta, Indonesia. In topography a summit is a point on a surface which is higher in Elevation than all points immediately adjacent to Central Java ( Provinsi Jawa Tengah) is a province of Indonesia. The Special Region of Yogyakarta ( Indonesian: Daerah Istimewa Yogyakarta, or DIY) is the smallest province of Indonesia (excluding The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. A geographic coordinate system enables every location on the Earth to be specified in three coordinates using mainly a spherical coordinate system. A geographic coordinate system enables every location on the Earth to be specified in three coordinates using mainly a spherical coordinate system. Mountains can be characterized in several ways Some mountains are Volcanoes and can be characterized by the type of lava and eruptive history A stratovolcano, also called a composite volcano is a tall conical Volcano composed of many layers of hardened Lava, Tephra, and Volcanic The geologic time scale is a chronologic schema (or idealized Model) relating Stratigraphy to time that is used by Geologists and other Plate tectonics and hotspots Divergent plate boundaries At the Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Indonesian or Bahasa Indonesia, based on the Riau version of Malay language, was declared the official language with the declaration of Indonesian or Bahasa Indonesia, based on the Riau version of Malay language, was declared the official language with the declaration of Plate tectonics and hotspots Divergent plate boundaries At the Central Java ( Provinsi Jawa Tengah) is a province of Indonesia. The Special Region of Yogyakarta ( Indonesian: Daerah Istimewa Yogyakarta, or DIY) is the smallest province of Indonesia (excluding The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. It is the most active volcano in Indonesia and has erupted regularly since 1548. Its name means Mountain of Fire. 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. Yogyakarta (also Jogja, Yogya, Jogjakarta) is a city in the Yogyakarta Special Region, Indonesia. Mean sea level (MSL is the average (mean height of the Sea, with reference to a suitable reference surface

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 43 people in 1994, mostly in the town of Muntilan, west of the volcano. Another large eruption occurred in 2006, shortly before the Yogyakarta earthquake. The May 2006 Java Earthquake occurred at 0554 local time on 27 May 2006 (2254 GMT 26 May) in the Indian Ocean In light of the hazards that Merapi poses to populated areas, it has been designated as one of the Decade Volcanoes. The Decade Volcanoes are 16 Volcanoes identified by the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI as being worthy

Geological history

Merapi before 2007 eruption.

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. In Geology, a subduction zone is an area on Earth where two tectonic plates meet and move towards one another with one sliding underneath the other The Indo-Australian Plate is a major Tectonic plate that includes the continent of Australia and surrounding Ocean, and extends northwest to include the The Eurasian Plate is a Tectonic plate which includes most of the continent of Eurasia (a landmass consisting of the traditional Continents of Europe 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. ^[1] 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. Lava is molten rock expelled by a Volcano during an eruption When first expelled from a volcanic vent it is a Liquid at Temperatures Basalt (bəˈsɔːlt ˈbeisɔːlt ˈbæsɔːlt is a common Extrusive Volcanic rock. Since then, eruptions have become more explosive, with viscous andesitic lavas often generating lava domes. For the extinct cephalopod genus see Andesites. Andesite (ˈændəsaɪt is an igneous, Volcanic rock, of intermediate In Volcanology, a lava dome or plug dome is a roughly circular Mound -shaped protrusion resulting from the slow eruption of Felsic Lava Dome collapse has often generated pyroclastic flows, and larger explosions, which have resulted in eruption columns, have also generated pyroclastic flows through column collapse. A pyroclastic flow (also known as a pyroclastic density current) is a common and devastating result of some volcanic eruptions. An eruption column consists of hot Volcanic ash emitted during an explosive Volcanic 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. Year 1786 ( MDCCLXXXVI) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a Common Year 1822 (MDCCCXXII was a Common year starting on Tuesday (see link for calendar of the Gregorian calendar (or a Common year starting on Sunday of the Year 1872 ( MDCCCLXXII) was a Leap year starting on Monday (link will display the full calendar of the Gregorian Calendar (or a Leap year Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar.

A very large eruption in 1006 is claimed to have covered all of central Java with ash. Volcanic ash consists of small Tephra, which are bits of pulverized rock and glass created by volcanic eruptions less than in diameter 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. A Hindu ( Devanagari: हिन्दू is an adherent of the philosophies and scriptures of Hinduism, a set of religious, Philosophical Mataram was an Indianized kingdom based in Central Java between the 8th and 10th centuries AD and was established by king Sanjaya, he was also known as

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. Surakarta (colloquially Solo) is an Indonesian city of approximately 500000 people located in Central Java. ^[2]

2006 eruption

Pyroclastic flows (2006)

In April 2006, increased seismicity at more regular intervals and a detected bulge in the volcano's cone indicated that fresh eruptions were imminent. Seismology (from Greek grc σεισμός seismos, "earthquake" and grc -λογία -logia) is the scientific study of Earthquakes 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 metres, compared to 75 metres the previous day. Events 1012 - Martyrdom of Alphege in Greenwich London. 1529 - At the Second Diet of Speyer 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. Events 215 BC - A temple is built on the Capitoline Hill dedicated to Venus Erycina to commemorate the Roman defeat at ^[3]

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^[4] and on May 13, Indonesian authorities raised the alert status to the highest level, ordering the immediate evacuation of all residents on the mountain. Events 330 - Byzantium is renamed ''Nova Roma'' during a dedication ceremony but is more popularly referred to as Constantinople Events 1497 - Pope Alexander VI excommunicates Girolamo Savonarola. ^[5] 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. ^[6] Activity calmed by the middle of May. ^[7]

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". Events 927 - Simeon the Great, Tsar of Bulgaria, dies 1120 - Richard III of Capua is anointed The May 2006 Java Earthquake occurred at 0554 local time on 27 May 2006 (2254 GMT 26 May) in the Indian Ocean The Special Region of Yogyakarta ( Indonesian: Daerah Istimewa Yogyakarta, or DIY) is the smallest province of Indonesia (excluding ^[8] 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. Events 1508 - Maximilian I Holy Roman Emperor, is defeated in Friulia by Venetian forces; he is forced to sign a three-year ^[9] The pyroclastic flows are known locally as "wedhus gembel" (Javanese for "shaggy goat").

Monitoring

Merapi Volcano January 27, 2007. Events 98 - Trajan becomes Roman Emperor after the death of Nerva. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century.

Merapi next to Merbabu January 9, 2008

Mount Merapi is the site of a very active volcano monitoring program. Mount Merbabu (Gunung Merbabu is a dormant Stratovolcano in Central Java province on the Indonesian island of Java. Events 475 - Byzantine Emperor Zeno is forced to flee his capital at Constantinople. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Seismic monitoring began in 1924, with some of the volcano monitoring stations lasting until the present. Seismology (from Greek grc σεισμός seismos, "earthquake" and grc -λογία -logia) is the scientific study of Earthquakes Year 1924 ( MCMXXIV) was a Leap year starting on Tuesday (link will display the full calendar of the Gregorian calendar. The Babadan (north west location), Selo (in the saddle between Merbabu and Merapi), and Plawangan monitoring stations have been updated with equipment over the decades since establishment. Mount Merbabu (Gunung Merbabu is a dormant Stratovolcano in Central Java province on the Indonesian island of Java. Plawangan is a hill above the town of Kaliurang, on the southern slopes of Gunung Merapi, Central Java, in Indonesia. During the 1950s and early 1960s some of the stations were starved of equipment and funds, but after the 1970s considerable improvement occurred with the supply of new equipment. Some of the pre-1930 observation posts were destroyed by the 1930 eruption, and newer posts were re-located. Similarly after the 1994 eruption, the Plawangan post and equipment were moved into Kaliurang as a response to the threat of danger to the Volcanological personnel at the higher point. Kaliurang is a small town located about 25 km north of the town of Yogyakarta, on the island of Java, Indonesia.

The eruption of 1930 was found to have been preceded by a large earthquake swarm. Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar. The network of 8 seismographs currently around the volcano allow volcanologists to accurately pinpoint the hypocentres of tremors and quakes. Seismometers (from Greek Seism - "the shakes" - and Metro - "I measure" are instruments that measure and record motions of the ground including The hypocenter or hypocentre (literally 'below the center' from the Greek υπόκεντρον) refers to the site of an earthquake or to that of a nuclear

A zone in which no quakes originate is found about 1. 5 km below the summit, and is thought to be the location of the magma reservoir which feeds the eruptions. A magma chamber is a large underground pool of molten rock lying under the surface of the earth's crust

Other measurements taken on the volcano include magnetic measurements and tilt measurements. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. Small changes in the local magnetic field have been found to coincide with eruptions, and tilt measurements reveal the inflation of the volcano caused when the magma chambers beneath it is filling up.

Lahars (a type of mudflow of pyroclastic material and water) are an important hazard on the mountain, and are caused by rain remobilizing pyroclastic flow deposits. A lahar is a type of Mudflow / Landslide composed of Pyroclastic material and Water that flows down from a Volcano, typically Mudslide redirects here it is also the name of a cocktail. A mudflow or mudslide is the most rapid (up to 80 km/h / 50 mph Rain is Liquid precipitation. On Earth it is the condensation of atmospheric Water vapor into drops heavy enough to fall often making it to Lahars can be detected seismically, as they cause a high-frequency seismic signal. Frequency is a measure of the number of occurrences of a repeating event per unit Time. Observations have found that about 50 mm of rain per hour is the threshold above which lahars are often generated.

See also

• List of volcanoes in Indonesia

References

Further reading

• Triyoga, Lucas Sasongko. Events 1508 - Maximilian I Holy Roman Emperor, is defeated in Friulia by Venetian forces; he is forced to sign a three-year Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. 1991 Manusia Jawa dan Gunung Merapi – Persepsi dan Sistem Kepercayaannya Yogyakarta, Gadjah Mada Universsity Press. ISBN 979-420-211-8
• Decker, R. and Decker, B. (1997) Volcanoes, 3rd edition, WH Freeman, New York.

External links

• Mount Merapi's activity continues to slow down (July 4, 2006)
• Live (30 minute) IR Satellite
• Live Volcanic Ash Advisories
• Map of Indonesian volcanoes active since 1900
• Global Volcanism Program entry
• Volcanological Survey of Indonesia
• Info and pictures
• Info and pictures
• A lot of sources concerning the Merapi-eruption in May 2006
• Map of population centers near Merapi (May, 2006)
• Merapi (and other Indonesian Volcanoes)overview and photos (June 6)
• The Independent Mount Merapi Observatory Balerante 149070-Info and Pictures of Merapi Activities