Since it began erupting earlier this month, Kilauea has proven to be both dangerous and beautiful. Oozing red rivers of lava have slowly made their way across the region surrounding the volcano on Hawaii's Big Island, while fountains of molten rock dance and spatter around the erupting fissures.

Now, the volcano is producing a new spectacle—blue flames.

Video published yesterday by the U.S. Geological Survey shows streaks of eerie blue flames springing up between cracks in a road. The otherworldly effect is caused by methane, which is being produced as dead vegetation breaks down and the gas builds up in underground voids. When the methane seeps out and ignites, it produces the strange scene. (Learn the difference between lava and magma.)

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