{"id":35489,"date":"2023-10-31T17:56:35","date_gmt":"2023-10-31T16:56:35","guid":{"rendered":"http:\/\/3b4b7ddc-2489-4b04-892c-99f8a9af103b"},"modified":"2023-10-31T19:46:47","modified_gmt":"2023-10-31T18:46:47","slug":"in-pictures-the-electric-blue-lava-pouring-from-earths-strangest-volcano","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/rss_feed\/in-pictures-the-electric-blue-lava-pouring-from-earths-strangest-volcano\/","title":{"rendered":"In pictures: The electric-blue lava pouring from Earth\u2019s strangest volcano"},"content":{"rendered":"

The luminous blue lava found on Java is caused by the sulphuric gasses burning in the oxygen-rich air once they reach the surface. <\/p>

By Ceri Perkins\n <\/p>

Published: Tuesday, 31 October 2023 at 16:56 PM<\/p>

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Most people \u2013 if they\u2019ve heard of it at all \u2013 are aware of \u2018blue lava\u2019 thanks to the otherworldly photographs of French photographer Olivier Grunewald. The images, which Grunewald captured at the Kawah Ijen volcano on the island of Java in Indonesia, seem to show rivers of electric-blue lava, incandescent against a black velvet night.<\/p>

Photo credit: O. Grunewald<\/figcaption><\/figure><\/div>

Despite appearances, however, it\u2019s not lava that produces the striking blue glow. Instead, it\u2019s combusting sulphuric gases, which belch from the volcano\u2019s many fumaroles at temperatures of up to 600\u00b0C (around 1,100\u00b0F).<\/p>

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Photo credit: O. Grunewald<\/figcaption><\/figure><\/div>

When the hot gases hit oxygen-rich air, they ignite and burn with a neon-blue flame. As they burn, some of the gases condense into molten sulphur, which continues to burn blue as it spills down the mountainside. By contrast, Kawah Ijen\u2019s actual lava emerges in the familiar red-orange colour<\/a> you see\u00a0at other volcanoes.<\/p>

\"Electric
Photo credit: O. Grunewald<\/figcaption><\/figure><\/div>

The flames\u2019 distinctive blue colour is caused by a phenomenon called electronic excitation. When the sulphuric gases burn, the intense heat \u2018excites\u2019 electrons within the sulphur atoms. This excited state is extremely unstable and the electrons revert almost immediately to their \u2018relaxed\u2019 state by shedding excess energy in the form of light.<\/p>

\"Blue
Photo credit: O. Grunewald<\/figcaption><\/figure><\/div>

All elements emit characteristic wavelengths of light during electronic excitation, corresponding to different colours of the visible spectrum. In the case of sulphur, that colour is the eerie blue-violet that tints the flames at Kawah Ijen.<\/p>

Locals refer to the phenomenon as Api Biru, or \u2018blue fire\u2019. Although the blue fire burns around the clock, its flames are difficult to make out in daylight; only as night falls does the spectacle begin to reveal itself.<\/p>

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Photo credit: O. Grunewald<\/figcaption><\/figure><\/div>

Api Biru is not unique to Kawah Ijen \u2013 Grunewald has also photographed the phenomenon at the Dallol volcano in the Danakil Depression in Ethiopia. But the Kawah Ijen\u2019s unusually high concentrations of sulphur deposits and sulphuric gases make it the most arresting example and the only one that is consistently burning.\u00a0<\/p>

Read more:<\/strong><\/p>