Why Does This Indonesian Volcano Burn Bright Blue?
by Joseph Stromberg
images by Olivier Grunewald
Over the past month, the web has come alive with French photographer Olivier Grunewald's spectacular photos of Indonesia's Kawah Ijen volcano. Snapped during shooting of a new documentary he’s releasing with the president of Geneva’s Society for Volcanology, Régis Etienne, the photos—taken without the aid of any filter or digital enhancement—showcase the volcano’s amazing electric blue glow.
See more of Grunewald’s images and read more about the volcano at Smithsonian.com.