See this spectacular video of lightning strikes near the eruption of a volcano on Mount Kirishima, which was shot by a nearby bystander. Be sure to go to full screen mode.
The Shinmoedake volcano on Mt. Kirishima, located on the Kyushu main island of southern Japan has erupted for three straight days, sending potentially hazardous ash and smoke into the air of towns nearby. News reports say this is its biggest eruption in 50 years.
For an explanation of how volcanoes cause lightning, Jearl Walker in his book The Flying Circus of Physics writes about a similar case of brilliant flashes of lightning dancing around the Icelandic volcano Surtsey in 1963.
“The hot lava hitting the seawater sends positively charged steam upward. After sufficient charge separation has occurred, the clouds of steam discharge back to the ocean, allowing electrons to flow upward through the ionization column. The upward flow of electrons is opposite the situation with normal lightning.”
In the case of Mt. Kirishima, fog and moist air from the nearby sea might be generating enough steam to create the flashes of lightning seen in the video. As National Geographic points out, scientists still aren’t sure what exactly causes the spectacular strikes of lightning near volcanos.
Jorge Salazar has conducted thousands of in-depth interviews with scientists in the process of creating science content for EarthSky. He also helps host the 90-second EarthSky podcasts. Jorge has a bachelor's degree in physics from the University of Texas at Austin. He knows a lot about a lot of different things. For EarthSky, he has explored subjects as diverse as nanotechnology, ecosystem-based management, climate change, global health, international environmental treaties, astrophysics and cosmology, and environmental security. His penetrating research style, poetic writing, and ability to track down and speak with Nobel prize-winning laureates, all make him a huge asset to EarthSky.