When thinking of a volcano a person thinks of lava, ash, and mudslides, but lightning? Yes I said lightning. This little understood and somewhat rare occurrence happens when the ash from the erupting volcano, ice particles, and rock fragments collide with each other, producing a static charge within the plume of ash created by the erupting volcano. This occurrence of events creates an amazing light show in the skies around the erupting volcano. These amazing events have been seen at Chile’s Chaitin volcano in May of 2008 and even more recently in January 2011 at Japan’s Shinmoedake peak; although amazing these events can become dangerous causing evacuations of the surrounding areas. These events are called dirty thunderstorms due to the fact that they are created by particles of ash and rock.
Sources: National Geographic, Geology.com