Ash plumes directly over erupting volcanoes have been known to generate lightning, and electrically charged ash has been found in previous plumes up to 30 miles (50 kilometers) from their source volcanoes. (See pictures of lighting in the Eyjafjallajökull volcano's ash plume.)

But according to a new study, electric ash from the Eyjafjallajökull volcano was found a record 745 miles (1,200 kilometers) away from the eruption.

At that distance, it wasn't energy from the eruption itself that charged the ash, said study co-author Giles Harrison, a meteorologist at the University of Reading in the U.K. Based on the average size and shape of particles in the ash, "any