Map of Ijen Crater, where sulfur is mined Bergelut dengan asap nan beracun

The Ijen volcano complex is a group of

composite volcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and peri ...

es located on the border between

Banyuwangi Regency Banyuwangi Regency is a regency ( id, kabupaten) of East Java province in Indonesia. This regency also known as ''the sun rise of Java'' because it is located at the easternmost end of Java Island. It serves as a port between Java and Bali. It i ...

and Bondowoso Regency of

East Java East Java ( id, Jawa Timur) is a province of Indonesia located in the easternmost hemisphere of Java island. It has a land border only with the province of Central Java to the west; the Java Sea and the Indian Ocean border its northern and ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Gui ...

. It is known for its blue fire, acidic crater lake, and labour-intensive sulfur mining. It is inside an eponymous larger

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

Ijen, which is about wide. The Gunung Merapi stratovolcano is the highest point of that complex. The name "Gunung Merapi" means 'mountain of fire' in the Indonesian language;

Mount Merapi Mount Merapi, ''Gunung Merapi'' (literally Fire Mountain in Indonesian and Javanese), is an active stratovolcano located on the border between the province of Central Java and the Special Region of Yogyakarta, Indonesia. It is the most ac ...

in central

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

and

Marapi The Marapi (), or Mount Marapi ( min, ڬونوواڠ ماراڤي, Gunuang Marapi) is a complex volcano in West Sumatra, Indonesia. Its name means ''Mountain of Fire'', and it is the most active volcano in Sumatra. Its elevation is . A number of ...

in Sumatra have the same etymology. West of Gunung Merapi is the Ijen volcano, which has a turquoise-coloured acidic

crater lake Crater Lake ( Klamath: ''Giiwas'') is a volcanic crater lake in south-central Oregon in the western United States. It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity. The lake partly fill ...

. The lake is the site of a labour-intensive

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...

mining operation, in which sulfur-laden baskets are carried by hand from the crater floor. The work is paid well considering the cost of living in the area, but is very onerous. Workers earn around US$13 per day and, once out of the crater, still need to carry their loads of sulfur chunks about three kilometers to the nearby Paltuding Valley to get paid. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones run east–west across the southern side of the caldera. The active crater at Kawah Ijen has a diameter of and a surface area of . It is deep and has a volume of . The lake is recognised as the largest highly acidic crater lake in the world. It is also a source for the river Banyupahit, resulting in highly acidic and metal-enriched river water which has a significant detrimental effect on the downstream river ecosystem. During a scientific expedition in 2001, the pH of the lake was measured at <0.3. On July 14–15, 2008, explorer

George Kourounis George Kourounis (born 22 May 1970), is a Greek-Canadian adventurer and storm chaser who specializes in documenting extreme weather and worldwide natural disasters. He presents the television series ''Angry Planet''. Storm chasing Kourounis has b ...

took a small rubber boat out onto the acid lake to measure its acidity. The pH of the water at the lake's edges was measured to be 0.5 and in the middle of the lake 0.13 due to a high concentration of

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular fo ...

Blue fire crater

Since ''

National Geographic ''National Geographic'' (formerly the ''National Geographic Magazine'', sometimes branded as NAT GEO) is a popular American monthly magazine published by National Geographic Partners. Known for its photojournalism, it is one of the most widel ...

'' mentioned the electric-blue flame of Ijen, tourist numbers have increased. The phenomenon has long been known, but midnight hiking tours are a more recent offering. A two-hour hike is required to reach the rim of the crater, followed by a 45-minute hike down to the bank of the crater. The blue fire is ignited sulfuric gas, which emerges from cracks at temperatures up to . The flames can be up to high; some of the gas condenses to liquid and is still ignited. Ijen is the largest blue flame area in the world. Local people refer to it as ''Api Biru'' (Blue Fire). The other location at which blue fire can be seen is in Dallol mountain,

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

Sulfur mining at Ijen

An active vent at the edge of the lake is a source of elemental

and supports a mining operation. Escaping volcanic gases are channeled through a network of ceramic pipes, resulting in condensation of molten sulfur. The sulfur, which is deep red in colour when molten, pours slowly from the ends of these pipes and pools on the ground, turning bright yellow as it cools. The miners break the cooled material into large pieces and carry it away in baskets. Miners carry loads ranging from up to the crater rim, with a gradient of 45 to 60 degrees, and then down the mountain for weighing. Most miners make this journey twice a day. A nearby sulfur refinery pays the miners by the weight of sulfur transported; as of September 2010, the typical daily earnings were equivalent to approximately $13 US. The miners often receive insufficient protection while working around the volcano and complain of numerous respiratory afflictions. There are 200 miners, who extract 14 tons per day — about 20% of the continuous daily deposit.

Media

Ijen and its sulfur mining was featured in the 1991

IMAX IMAX is a proprietary system of high-resolution cameras, film formats, film projectors, and theaters known for having very large screens with a tall aspect ratio (approximately either 1.43:1 or 1.90:1) and steep stadium seating. Graeme ...

film ''

Ring of Fire The Ring of Fire (also known as the Pacific Ring of Fire, the Rim of Fire, the Girdle of Fire or the Circum-Pacific belt) is a region around much of the rim of the Pacific Ocean where many volcanic eruptions and earthquakes occur. The Ring ...

'', and as a topic on the 5th episode of the BBC television documentary '' Human Planet''. In the documentary film ''

War Photographer ''War Photographer'' is a documentary by Christian Frei about the photographer James Nachtwey. As well as telling the story of an iconic man in the field of war photography, the film addresses the broader scope of ideas common to all those inv ...

'',

journalist A journalist is an individual that collects/gathers information in form of text, audio, or pictures, processes them into a news-worthy form, and disseminates it to the public. The act or process mainly done by the journalist is called journalis ...

James Nachtwey James Nachtwey (born March 14, 1948) is an American photojournalist and war photographer. He has been awarded the Overseas Press Club's Robert Capa Gold Medal five times and two World Press Photo awards. In 2003, Nachtwey was injured in a gre ...

visits Ijen and struggles with noxious fumes while trying to photograph workers.

Michael Glawogger Michael Glawogger (3 December 1959 – 23 April 2014) was an Austrian film director, screenwriter and cinematographer. From 1981 to 1982, Glawogger studied at the San Francisco Art Institute, and from 1983 to 1989 at the Vienna Film Academy. Li ...

's film ''

Workingman's Death ''Workingman's Death'' is a 2005 Austrian-German documentary film written and directed by Michael Glawogger. It premiered at the 2005 Venice Film Festival. The film deals with the extremes to which workers go to earn a living in several countrie ...

'' is about sulfur workers.

Gallery

File:Kawah Ijen volcano, Java.jpg, Kawah Ijen volcano and crater lake, Java, viewed from

Landsat 8 Landsat 8 is an American Earth observation satellite launched on 11 February 2013. It is the eighth satellite in the Landsat program; the seventh to reach orbit successfully. Originally called the Landsat Data Continuity Mission (LDCM), it is a ...

File:The cauldron of Ijen Mountain, Indonesia.jpg, The sulfuric lake of Kawah Ijen Mountain's cauldron, Indonesia File:Mount Merapi Ijen A.JPG, Mt. Merapi, Ijen File:Ornament of sulfur.jpg, Sulfur ornaments from Ijen mines File:The blue fire of Kawah Ijen 1.jpg, The blue fire of Kawah Ijen File:Kawah Ijen sulfur mining - Indonesia.jpg, Kawah Ijen sulfur mining File:Kawah Ijen sulfur miner - Indonesia.jpg, Kawah Ijen sulfur miner File:Kawah Ijen - Indonesia.jpg, Kawah Ijen

References

External links