Amazing Lightning Photograph

Written By: Brian Neudorff

This is a photograph of what? The storm that destroyed Greensburg, KS over a year ago? Maybe it is a picture of thunderstorms over Oklahoma and Missouri last weekend? Or it could be cyclone Nargis before it devastated Myanmar?

The lightning in this picture was not caused by any atmospheric storm but by the cloud of ash and gasses associated with last weeks eruption of Chile's Chaitén volcano on May 3, 2008.

This little known and understood phenomenon is called a "dirty thunderstorm." It is thought to be sparked when rock fragments, ash, and ice particles in the plume collide to produce static charges—just as ice particles collide to create charge in regular thunderstorms.

For more information on "dirty thunderstorms" you can visit the National Geographic article "Volcanic Lightning Sparked by 'Dirty Thunderstorms,' Study Finds" [February, 2, 2007].

Source: NationalGeographic.com (PHOTOS: Chile Volcano Erupts With Ash and Lightning)