The Kawah Ijen Volcano, the largest sulfuric acid crater lake in the world, spews blue lava.
These pictures are not Photoshopped. The Ijen Volcano of Java Island brightens the night with its electric blue flames and lava, which are surrounded by a one-kilometer-wide turquoise lake that identified as the “largest highly acidic crater lake in the world.” It has a pH balance of 0.5 due to sulfuric acid.
The Ijen Volcano sits in the Banyuwangi - Bondowoso Region of East Java in Indonesia. The sulfur reacts with the air when the lava breaches the surface, combusting into blue lava rivers.
Locals call the caldera surrounding Ijen “Gunung Merapi” which means Mountain of Fire. The burning continues twenty-four hours a day, but it’s most visible in darkess. The flames rise up to five meters high. Some of the gas condenses to liquid and still burns. Locals dubbed those instances “Blue Fire.”
Stratovolcanoes are conical volcanoes built up by many layers of tephra, hardened lava, volcanic ash, and pumice. They can be identified by steep profiles, and effusive and periodic explosive eruptions. Some stratovolcanoes have collapsed craters called calderas.
The volcano emits hydrogen chloride gas, which reacts with water to form Kawah Ijen lake. The water’s pH balance is almost 0 and highly concentrated with hydrochloric acid.
“Those gas are emerging from cracks in the volcano at high pressure and temperature, up to 1,112°F (600°C). When they come in contact with the air, they ignite, sending flames up to 16 feet (5 meters) high.
Some of the gas condense into liquid sulfur, which continues to burn as it flows down the slopes, and giving the feeling of lava flowing.”
Grunewald and filmmaker Regis Etienne produced a documentary about the volcano called Kawah Ijen, the Mystery of the Blue Flames.
Source : Interesting Engineering | Wikipedia | National Geographic