‘Dirty thunderstorm’: Lightning in a volcano

The Iceland volcano Eyjafjallajokull continued to erupt on April 19, sending out a plume of ash and lightning and offering a rare glimpse at the mysterious electrical phenomenon known as a “dirty thunderstorm.”

Another view of Eyjafjallajokul on April 19. Evidence collected in January 2006 following the initial volcanic eruptions of Mount Augustine in Alaska revealed that eruptions produce a large amount of electric charge.

The Iceland volcano Eyjafjallajokull, photographed on April 19. The activity may be similar to that observed by scientists following Mount Augustine's 2006 eruption in Alaska: “Continuous radiation and bursts of lightning within the rock and ash as it rushed upward from the vent,” reports Far North Science.

Volcanic eruptions are lit by lightning on the Eyjafjallajokull glacier on April 18. Scientists who studied the Mount Augustine eruption concluded that the lightning occurred in two phases, reports Far North Science. “In a process that had never been documented before, the first series of zapping bolts occurred because the ash and rock and other debris emerged from the volcano’s throat already loaded with a high positive electrical charge.”

Volcanic eruptions are lit by lightning on the Eyjafjallajokull glacier on April 18. Scientists are unsure whether the charge comes out of the volcano or is created closer to the atmosphere following an eruption.

Volcanic eruptions are lit by lightning on the Eyjafjallajokull glacier on April 18. In conventional thunderstorms, electric charges are sparked when ice particles collide.

Volcanic eruptions on the Eyjafjallajokull glacier on April 18. Low-energy lightning is sometimes active during eruptions, arcing between particles as they exit the volcanic vent at around 100 metres per second.

Volcanic eruptions on the Eyjafjallajokull glacier on April 18.

Volcanic eruptions on the Eyjafjallajokull glacier on April 18.

Volcanic eruptions on the Eyjafjallajokull glacier on April 18.

The Eyjafjallajokull volcano, Iceland, photographed on April 17. In “dirty thunderstorms," scientists believe that static charges are ignited by ice particles, as well as ash and rock fragments from the volcano.