Eruption of Japan's Sakurajima volcano in February 2013
The fusion of flash with ash! Say the words aloud, together, and it sounds impossible – the kind of thing a six-year-old might think up...
Few phenomena can compete with the raw beauty and devastating power of a raging thunderstorm, save for a particularly violent volcanic eruption. But when these two forces of nature collide, the resulting spectacle can be so sublime as to defy reason. The photograph above offers some important insights into the formation and study of volcanic lightning. It was taken late last month by German photographer Martin Rietze, on a visit to Japan's Sakurajima volcano.
Another theory is that lightning may be caused by charge-inducing collisions in volcanic dust. The phenomenon has been photographed recently in several volcanic eruptions, from Iceland to Indonesia.