Blue Lava

One of the most destructive occurrences in our world is the explosion of a volcano. But in Indonesia, the Kawah Ijen crater on the island of Java appears to stream blue lava instead of the traditional orange and yellow tone.

This produces a confusion as the lava is not inherently blue, the glow is actually due to the light from the combustion of sulfuric gases.These gases emerge from cracks in the volcano at high pressure and temperature -- up to 1,112°F (600°C). When they make contact with the air, they ignite,producing a blue glow and sending flames up to 5 metres high.Because only the flames are blue, rather than the lava itself, the effect is only visible at night—during daytime, the volcano looks like roughly any other.

Some of the gases condense into liquid sulfur, "which continues to burn as it flows down the slopes," said Grunewald, "giving the feeling of lava flowing."

A River of Sulfur flows into the Lake

Grunewald and Etienne produced the documentary partly to bring attention to these harsh working conditions. Most of the miners do not have gas masks (which the photographers wore throughout shooting and distributed to miners afterward), and suffer from health problems due to prolonged exposure to sulfur dioxide and other toxic gases.

Shooting these striking photos—some taken just a few feet away from the flames—was far more physically demanding than most of Grunewald's previous projects of landscapes and wildlife. "The main problem was the acidic gases that whirled constantly in the crater," he says. "The night seriously increased the difficulty as well, because it became almost impossible to see when dense gases arrived—at times, we were stuck in gas plumes for over an hour without being able to see our hands."

Another image of the beautiful phenomena

Just 30 nights in the crater, distributed over six trips, were enough to show Grunewald how destructive the environment of these mines can be. "During my first trip, I lost a camera and two lenses that had been corroded by acid," he says. "After we got back home, it took up to three weeks for our skin to lose the smell of sulfur."

His photos make the blue flames appear dramatically beautiful, even surreal. But for the miners that spend months or years at the volcano, the sulfur dioxide is quite real, and the health effects of chronic exposure—throat and lung irritation, difficulty breathing and a propensity for lung disease—can be devastating.