Submitted by admin on Wed, 09/29/2010 - 03:16

 

 

Dieng Volcanic Complex (also called the Dieng Plateau) is a complex volcano. A complex volcano is an extensive assemblage of spatially, temporally, and genetically related major and minor volcanic centers with their associated lava flows and pyroclastic rocks (Francis, 1994). The Dieng Volcanic Complex forms a large depression about 9 miles (14 km) long and about 4 miles (6 km) wide and elongated in a northwest-southeast direction. This larger structure may be a caldera associated with the relics of two or more stratovolcanoes. However, no large volume deposit(s) associated with a caldera-forming event have been identified. If a caldera is involved it is older than 16,000 years. Sketch map of Dieng Plateau and caldera from Newhall and Dzurisin (1988) and modified from Delarue (1980).

Within the complex are numerous cones, many of which are 30-100 feet (100-300 m) high. Most cones are made of cinders or ash. Lava flows are less common. This photo shows Kawah Sibanteng, one of the larger cones in the Dieng complex. All photos by Steve Mattox.

Telaga Warna is a lake within a broad, low-relief cone. Gas bubbles are seen rising to the surface of the lake and the air has a sulfurous odor.

Terraced fields along the southeast margin of the Dieng Volcanic Complex. Potatoes are a common crop on the plateau.

A solfatara field is located on the east flank of Kawah Sikidang.

In addition to vents for gases there are boiling mud pots near the solfatara.
Panorama of Telaga Merdada, a broad, low-relief cone which may be a maar.

Looking east to Dieng Village. Note the steep cliffs (caldera rim?) in the background along the northeast part of the complex.

The Arjuna, a group of Shiva temples, is located on east-central part of the volcanic complex. These are the oldest Hindu temples in Java, built in 8th and 9th centuries. The name "Dieng" comes from "Di Hyang" which means Abode of the Gods. The plateau was once the site of over 400 temples. There have been at least 18 historic eruptions at Dieng since 1375. Most of these eruptions are phreatic and small to moderate (VEI=1-2) in explosivity. Eight of the eruptions have been explosive. The eruption in 1375 was VEI of 3. Eight eruptions have caused fatalities. In 1786, ground fissuring destroyed the village of Jamping killing 38 people. Eruptions in 1826 and 1827 caused several fatalities. The eruption near Timbang in 1928 killed about 40 people, one by falling rock. Steam explosion in 1939 killed 10 people at Timbang and lahars destroyed 50 hectares. During the 1944 eruption ash and blocks of old volcanic material rained on seven villages and caused an estimated 117 deaths and 250 injured. Some wounds were caused by boiling mud. All casualties were within about 0.6 mile (1 km) of the vent. The 1964 eruption caused 114 deaths. The most recent fatal eruption was in 1979. A phreatic eruption was preceded by at least three felt earthquakes. At least 149 people were killed by poisonous gas(es) as they fled phreatic eruptions at Sinila and Sigludung craters. The bodies were found along the track leading to Batur (the people were single file along the track and seeming to be asleep). The gases were either carbon dioxide (CO2) or carbon dioxide and hydrogen sulfide (H2S). Over 1,000 people were injured with 100 of these requiring hospitalization. About 15,000 people were evacuated from 6 villages near Sinala. The gas(es) also killed livestock and fish. Newhall and Dzurisin (1988) noted that Delarue (1980) distinguished four types of phreatic and phreatomagmatic eruptions at Dieng:

 

  1. phreatic eruptions as a result of self sealing (for example, Kawah Sileri, 1943-1944; Candradimuka, 1945; and Sikidang);
  2. phreatic eruptions as a result of tectonic fissuring that allows hot ground water to flash to steam (for example, Timbang, 1928, 1939);
  3. phreatomagmatic eruptions as a result of fissuring during dike intrusion, which allows hot ground water to flash to steam (for example, Kendil);
  4. rootless phreatic explosions as a result of lava entering a body of surface water (for example, at Pakuwojo).

 

Eruptions in the central and northeastern parts of the Dieng Complex are of the type 1, and those in the western part are mainly of type 2. The best examples of types 3 and 4 are in the southeastern part of the complex. Eruptions of type 1 are not preceded by notable seismicity. Eruptions of type 2 and 3 are preceded by notable seismicity and surface faulting.

Photograph of andesite lava flow of the Dieng Volcanic Complex. Geochemistry of rocks from the Dieng Volcanic Complex.
Sample Basalt of
Telogo Mendjer		 Andesite 
of Pangonan		 Andesite 
of Pakuwodjo
SiO2 51.19 55.64 62.93
Al2O3 20.02 17.91 14.37
Fe2O3 3.69 3.91 3.97
FeO 5.24 5.13 2.78
MnO 0.15 0.14 0.09
MgO 3.45 3.20 2.31
CaO 9.75 7.16 4.38
Na2O 3.38 3.65 3.16
K2O 1.42 2.07 3.29
H2O+ 0.64 0.62 1.33
H2O- 0.30 0.45 0.51
TiO2 1.05 0.93 0.69
P2O5 0.17 0.15 0.05
Total 100.45 100.24 99.86

 

All analyses from Van Bemmelen (1947) as reported in Neumann van Padang (1951).

 

Andesite of Pangonan contains augite and hypersthene. Andeite of Pakuwodjo contains augite, hypersthene, and biotite. Giggenbach and others (1992) used the isotopic composition of helium and carbon to identify a mostly magmatic source for the gases at the Dieng Volcanic Complex.

Geothermal energy is being developed in the central and east parts of the complex to generate electricity. This photo shows a well head.

Looking west along the northwest part (rim?) of the Dieng complex from west of Kawah Sileri.

Sources of Information:

Bemmelen, R.W., van, 1949, Report on the volcanic activity and volcanological research in Indonesia during the peeriod 1936-1948. Bulletin Volcanologique, II, 9, Napoli 1949, p. 23-24.

Delarue, C., 1980, Exploration geothermique dans la region de Dieng (java): Univ. Paris XI, unpubl. Ph.D. thesis, 247 p.

Francis, P., 1994, Volcanoes a planetary perspective: Oxford University Press, New York, 443 p.

Giggenbach, W.F., Sano, Y., and Schmincke, H.U., 1991, CO2-rich gases from Lake Nyos and Monoun, Cameroon; Laacher See, Germany; Dieng Indonesia, and Mt. Gambier, Australia - variation on a common theme: Journal of Volcanology and Geothermal Research, v. 45, p. 311-323.

LeGuern, F., Tazieff, H., and Faivre Pierret, R., 1982, An example of health hazards: people killed by gas during a phreatic eruption: Dieng Plateau, Java, Indonesia, Bulletin of Volcanology, v. 45, p. 153-156.

Miller, C.D., Sukhyar, R., Santoso, and Hamidi, S., 1981, Eruptive history of the Dieng Mountains region, central Java, and potential hazards from future eruptions: U.S. Geol. Survey Open-File Report 83-68, 26 p.

Muffler, L.J.P., 1970, Geothermla potential of the Dieng Mountains, central Java, Indonesia: U.S. Geol. Survey Project rep. (IR) IND-10, 20 p.

Newhall, C.G., and Dzurisin, D., 1988, Historical unrest at large calderas of the world: U.S. Geological Survey Bulletin 1855, v. 2, p. 755-772.

Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.

Neumann van Padang, M., 1951, Indonesia. Catalogue of the Active Volcanoes of the World, International Association of Volcanology, 1, Rome, Italy, p. 271

 

Latitude (DD): 
-7.20
Longitude (dd): 
109.90
Elevation (m): 
2565
State (Province, etc): 
Java
Google Maps: 
http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode=&q=7.2S%2C%20109.9E&sll…
More Images: 
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Country: 
Indonesia
Type: 
Complex