Sunday, 16 November 2014

Dirty Thunderstorms

Dirty thunderstorms - also known as volcanic lightning - are a breathtaking natural phenomenon where powerful forks of lightening are formed within the plume of a volcanic eruption. As the hot ash that forms the eruption column is forced toward the sky these dramatic bolts of lighting strike downwards. They look as if they have been forged within the inner circles of hell. Dirty thunderstorms are a fiercely visual reminder that no matter how powerful the human race believes itself to be, mother nature is still in-charge.

As a volcano erupts, lava and hot ash spill out of the crater causing mass havoc and destruction to the surrounding area. On rare occasions within a volcanic plume, electrical charges are formed which in turn create a dirty thunderstorm. However, for these electrical charges to be formed, the volcanic eruption has to be somewhat significant. The reason these lightning strikes within the hot ash cloud materialise, is due to the simple fact that opposites attract. A large negative charge within the volcanic ash cloud effectively searches for a connection with a large positive charge - which is usually contained within the earth below. This is why lightning strikes downwards and not upwards. Once these charges have located each other, the electrons that connect the two explode emitting a mass radiation of heat. This explosion of the connecting electrons is so violent that it causes a gigantic flash, also known as lightning. This lightning is approximately 2-5 cm wide and can reach a temperature of 30,000 kelvins (29,726 Celsius), which believe it or not, is roughly five times the temperature of the surface of the sun. The intense heat and dramatic flash that this dirty thunderstorm lightning creates lasts around 1-2 microseconds; and the large crack of thunder that it emits will be 120 db, on average. This is roughly the same volume that you would experience if you sat directly in-front the speakers at a rock concert.

Although this phenomenon is relatively widespread, the most famous cases have been documented within Chile above the Chaiten volcano - which last erupted in 2008 -; in Alaska above the Mt Augustine volcano - which covers an area of 84 sq km (32 sq miles) -; and in Iceland above the easy to pronounce Eyjafjallajokull volcano - which is famous for the 2010 eruption that caused mass havoc across Europe, causing many flights to be cancelled and many holidays to be postponed.

Much is still to be discovered about dirty thunderstorms, due to the inability of scientists to encroach upon them without potentially encountering an electrifying or molten lava induced death. However, one things is known for sure: they have undoubtedly captured our imagination.

Lightning strikes can reach a temperature that is five times hotter than the surface of the sun.

Eyjafjallajokull volcano, Iceland. This volcano was responsible for the 2010 air traffic disturbances in Europe.

A terrifying looking dirty thunderstorm. 

- Until the next Butterfly...