The Physics of the Plasma Universe by Anthony Peratt describes magma as a plasma, a medium containing moving charges. So we should expect volcanoes not only to exhibit electrical behavior but to have that behavior connected with the larger plasma environm
We had a fantastic lightening storm last nite, Aug Booms, low rumbles, actual lightening bolts (not the typical sheet lightening). Haven't had a good one in SW Puget Sound for years. a really good picture of an amazing set of lightning strikes.