Although it is thought to have a small effect on the overall charging of volcanic plumes , naturally occurring radioisotopes within ejected rock particles may nevertheless influence particle charging . In a study performed on ash particles from the Eyjafjallajökull and Grímsvötn eruptions , scientists found that both samples possessed a natural radioactivity above the background level , but that radioisotopes were an unlikely source of self-charging in the Eyjafjallajökull plume . However , there was the potential for greater charging near the vent where the particle size is larger . Research continues , and the electrification via radioisotopes , such as radon , may in some instances be significant and at various magnitudes a somewhat common mechansim
Grímsvötn
2011 eruption of Grímsvötn
Volcanic lightning