Why Eerie Blue Flames Just Erupted from Hawaiian Volcano

When red-hot lava buries plants and shrubs, the burning vegetation produces methane, a colorless gas that burns blue, according to the U.S. Geological Survey (USGS).

When methane is heated, it can seep into voids below the surface — in this case, the cracks on Kahukai Street in the residential area of Leilani Estates. Heated methane can explode, but when it was ignited on Tuesday night, its blue flames simply burned out of the fractures in the road, several feet away from the lava, the USGS reported. [Photos: Fiery Lava from Kilauea Volcano Erupts on Hawaii's Big Island]

"It's very dramatic. It's very eerie," Jim Kauahikaua, a USGS scientist, told the Associated Press. This is only the second time in his career that he's seen blue flames during an eruption, Kauahikaua said.

These eerie blue flames are actually burning methane. (Image credit: U.S Geological Survey)

About 2,000 people have evacuated from Leilani Estates and adjacent neighborhoods since the Kilauea volcano began erupting in early May. More than 20 fissures have opened, pouring lava and volcanic gases such as sulfur dioxide into the area.

One man was even hit on the leg by a "lava bomb" — a glob of molten lava that was ejected from the volcano — and lived to tell the tale. The eruption has destroyed about 50 buildings, including about two dozen homes.

This map shows current and historical lava flows on Hawaii's Big Island. The blue flames burned in the Leilani Estates. The light purple areas on the map show where lava flows erupted in 1840, 1955, 1960 and 2014-15. The pink and red areas show where lava has flowed, and is flowing, during this eruption. (Image credit: U.S Geological Survey)

Original article on Live Science.

Laura Geggel
Editor

Laura is the archaeology and Life's Little Mysteries editor at Live Science. She also reports on general science, including paleontology. Her work has appeared in The New York Times, Scholastic, Popular Science and Spectrum, a site on autism research. She has won multiple awards from the Society of Professional Journalists and the Washington Newspaper Publishers Association for her reporting at a weekly newspaper near Seattle. Laura holds a bachelor's degree in English literature and psychology from Washington University in St. Louis and a master's degree in science writing from NYU.