The Blue Fire of Ijen

Ijen is a group of composite volcanoes. It sits inside a caldera about 20 kilometres wide.

West of Gunung Merapi lies a one-kilometre-wide crater lake. It is the largest highly acidic crater lake. Not ideal for a casual swim.

On 14–15 July 2008, George Kourounis measured the lake center at pH 0.13. Sulfuric acid really commits.

At night, ignited sulfuric gas emerges from cracks. This creates electric-blue flames up to 5 meters high.

Sulfuric gas burns blue at extreme heat.

Escaping volcanic gases are channeled through ceramic pipes, condensing molten sulfur.

There are 200 miners who extract 14 tons per day. They carry loads ranging from 75 to 90 kilograms.

Miners make this journey twice a day, earning around US$13. That buys exactly zero sympathy from the volcano.