What is Volcanic lightning?

Volcanic lightning is a rare and dramatic natural phenomenon that occurs during volcanic eruptions, not thunderstorms. It appears as powerful flashes of lightning striking through plumes of ash, smoke, and gas spewing from an erupting volcano — creating an eerie, almost otherworldly sight.

How It Happens

• In a normal thunderstorm, lightning occurs when electrical charges build up and discharge between differently charged regions of a cloud.
• In a volcanic eruption, the process is somewhat similar but involves volcanic ash particles instead of water droplets.
• As ash, dust, and rock fragments are ejected into the air, they collide and rub together, generating static electricity.
• This buildup of electric charge eventually discharges in the form of lightning flashes within or above the volcanic plume.

Where It Occurs

Volcanic lightning can happen in two regions:

1. Near the ground, in dense ash clouds surrounding the volcano’s vent.
2. Higher in the eruption plume, where the ash and gases rise and mix with the atmosphere.

Why It’s Dangerous

• The combination of molten lava, ash, toxic gases, and lightning makes volcanic eruptions extremely hazardous.
• The lightning itself can ignite fires, damage equipment, and make rescue or monitoring operations dangerous.

Historical Note

The earliest recorded instance of volcanic lightning comes from Pliny the Younger, an ancient Roman writer and magistrate, who described it during the eruption of Mount Vesuvius in 79 AD — the same eruption that buried Pompeii.

Source: TH