VOLCANO GUIDE

CLIMBING ACTIVE VOLCANOES IN INDONESIA

MERAPI VOLCANO (2968m ASL)

Merapi Volcano

Merapi Volcano is the most active volcano in Indonesia. Some experts also said that this 2,968 m ASL (9,738 ft) high Volcano is also included as the most dangerous volcano in the world. It has erupted regularly since 1548. Typically, small eruptions occur every two to three years, and larger ones every 10–15 years or so. Remarkable eruptions, often causing many deaths, have occurred in 1006, 1786, 1822, 1872, and 1930. Thirteen villages were destroyed and 1400 people killed by the hot pyroclastic flows. Smoke can be seen emerging from the mountain top at least 300 days a year, and several eruptions have caused fatalities. Hot gas from a large explosion killed 27 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. 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.

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 out flowing 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

Seismic monitoring for Merapi began in 1924, with some of the volcano monitoring stations lasting until the present. There are several observatory posts around Merapi, the Babadan (northwest location), Selo (in the saddle between Merbabu and Merapi), and Plawangan monitoring stations. All the station have been updated with modern equipments over the decades since establishment. 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.

On 25 October 2010 the Indonesian government raised the alert for Mount Merapi to its highest level and warned villagers in threatened areas to move to safer ground. People living within a 20 km (12.5 mile) zone were told to evacuate. Officials said about 500 volcanic earthquakes had been recorded on the mountain over the weekend of 23–24 October, and that the magma had risen to about 1 kilometre (3,300 ft) below the surface due to the seismic activity. On the afternoon of 25 October 2010 Mount Merapi erupted lava from its southern and southeastern slopes. The Volcano was still erupting on 30 November 2010 however due to lowered eruptive activity on 3 December 2010 the official alert status was reduced to level 3. 353 people were killed during the 2010 eruptions, many as a result of the pyroclastic flows. The ash plumes from the volcano also caused major disruption to aviation across Java.

The volcano is located approximately 28 kilometres (17 mill) north of Yogyakarta city, and thousands of people live on the flanks of the volcano, with villages as high as 1,700 metres (5,600 ft) above sea level. The name Merapi could be loosely translated as 'Mountain of Fire'. The etymology of the name came from Meru and Api, from the Javanese combined words, Meru means "mountain" refer to mythical mountain of Gods in Hinduism, and api means "fire". There is annual ceremony, according to the local tradition, function to keep the volcano quiet and to appease the spirits of the mountain. For Yogyakarta people, Merapi holds significant cosmological symbolism, because it is forming a sacred north-south axis line between Merapi peak and Southern Ocean (Indian Ocean). The sacred axis is signified by Merapi peak in the north, the Tugu monument near Yogyakarta main train station, the axis runs along Malioboro street to Northern Alun-alun (square) across Keraton Yogyakarta (sultan palace), Southern Alun-alun, all the way to Bantul and finally reach Samas and Parangkusumo beach on the estuary of Opak river and Southern Ocean.

This sacred axis connected the spirits of mountain revered since ancient times—often identified as "Mbah Petruk" by Javanese people—The Sultan of Yogyakarta as the leader of the Javanese kingdom, and Nyi Roro Kidul as the queen of the Southern Ocean, the female ocean deity revered by Javanese people and also mythical consort of Javanese kings. The Javanese regularly bring offerings for Merapi on the anniversary of the sultan of Yogyakarta's coronation.