...The scientists now believe that volcanoes can produce two kinds of lightning during an eruption. The first type, which has been understood for some time, occurs in the volcano's smoke plume a few minutes after the eruption ends. In this case, highly energized hot air and gases clash with the cool atmosphere, creating the sort of "organized," branched lightning found in a thunderstorm, says Thomas.

The second kind of lightning, which the authors called "a newly identified explosive phase," came as a surprise, says Thomas. As magma, ash and rocks spewed from Augustine carrying great electrical charge, they created continuous, chaotic sparks near the mouth of the volcano.

"There's some mechanism in there that's making it come out charged," says Thomas, who hopes the new observations will lead to a better understanding of both kinds of volcanic lightning.

Not all volcanic eruptions produce lightning, says McNutt, but the new equipment might be used to track the ones that do-particularly those in remote regions.