Volcanoes are the center of folklore and myth wherever they exist. These fiery mountains prone to unexpectedly erupting in cascades of lava and ash have inspired and frightened humans for centuries. However, there is one volcano that has a reputation that surpasses all others, Indonesia’s Kawah Ijen volcano, otherwise known as the blue volcano.

The active Kawah Ijen Volcano is part of a complex of volcanoes in Banywang Regency, Java. This popular complex is situated within Ijen crater with stratovolcano Gunung Merapi as the highest point. It is one of the world's most unusual volcanoes because instead of producing the usual red lava and black smoke, its underground activities result in bright blue flames rising into the air. Some people even call it electric blue fire. Since it was mentioned on TV (National Geographic to be precise) the number of tourists who travel to East Java and Indonesia has significantly increased.

The phenomenon is caused when the volcano's sulfuric gases come into contact with air temperature above 360°C.

The Ijen volcano complex has some of the highest levels of sulfur in the world. This dense collection of the gas, when exposed to oxygen and lit by the molten hot lava burns blue. Unlike regular volcanoes whose bright red lava is visible in the day, Kawah Ijen’s blue burning flames can only be seen at night. “The vision of these flames at night is strange and extraordinary,” Photographer Olivier Grunewald says. “After several nights in the crater, we felt really living on another planet.”

Here you can also find the largest acid lake in the world which is conveniently situated within the crater. While the turquoise water of this crater lake is quite spectacular, it can also threaten your life.

Sulfur Mining at Kawah Ijen

The Ijen volcano complex holds another, darker secret. It is home to one of the world's most dangerous sulfur mining operations in the world.

Miners extract the sulfur rock, which is formed after the blue flames extinguish leaving behind a solid sulfur-rich rock. They then carry these large loads in baskets down the side of the mountain to be paid per kilogram. The work is unregulated and small children can often be seen scrambling up and down the slopes hoping to support their families low incomes with additional money. They usually take two daily trips. Each local worker is paid about 680 Indonesian rupiahs per kilogram, the equivalent of about six USD cents.

The working conditions are highly dangerous. It does not only require agility and strength to walk up and down the volcano's steep slopes, but workers are also exposed to the toxic sulfur gases for long periods of time. Without gas masks or other safety equipment, many of the mine's workers suffer long-term health problems resulting from sulfur exposure. These volcanic materials make it one of the more dangerous places on Earth.

Documentary casts light on incredible workers

Photographer Olivier Grunewald worked with the president of the Geneva Society for Volcanology, Régis Etienne to create a documentary about the mining operation at Ijen. He describes working on the challenging project saying: “The main problem was the acidic gases that whirled constantly in the crater”.

Visitors to East Java can take a guided group tour at night to the volcano to see the blue flame phenomenon for themselves. Don't forget to schedule your trip and get a guide as the whole place can be quite dangerous!

Would you like to visit this part of the world? Have you seen a similar color in nature?

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