Volcanic eruptions are more than just lava flow. Many events happen including earthquakes, gas expelling, rocks being forced out and ash shooting up into the air. Did you know there is also something called a "dirty thunderstorm" associated with volcanoes? A dirty thunderstorm is an expression that has been given to describe the electrical discharges of lightning that occur during a volcanic eruption.
National Geographic reported on the intriguing presence of volcanic lightning in 2007 as a study was published in the journal Science. National Geographic wrote,
"The findings offer a rare glimpse of this poorly understood phenomenon, including evidence of one type of lighting never seen before by scientists". 1
This occurrence was difficult for scientists to track in previous years, but as more tools and knowledge become available, experts are hoping and beginning to be able to shed some light on this phenomenon. Although even fast forward to 2014, a lot is still unknown.
Since the 2007 report, volcanic lightning has been followed and photographed when eruptions from volcanoes occur. It is said this exceptional type of lightning is a unique type of electrical discharge that comes from volcanic plumes. It can be as short as 3 feet (1 meter) and last very briefly.
While the discovery of a dirty thunderstorm has been made, what generates the lightning is less clear. Experts believe the lightning is "sparked off" by infinite amounts of small fragments of ice that bang into one another inside the "turbulent thundercloud." Each time the ice fragments collide with each other, they generate static electricity that eventually grows large enough to create a massive spark which is then emitted as the lightning.
There are at least 2 to 3 different types of volcanic lightning. Some experts suggest there may even be other types not yet observed.
National Geographic also reported that particles colliding into one another are what create the lightning, indicating rock and ash are also a part of the ingredients that make up the recipe for a dirty thunderstorm.
In February 2010 National Geographic released a follow-up article about dirty thunderstorms. In the three years since the original report, a better ability to measure had been developed and various instruments were installed near the vents of an Alaskan volcano, Redoubt.
Volcanic seismologist, Steve McNutt, who studied the volcanic action in Alaska stated, "Both types of bigger, more obvious bolts occur when water droplets and ice particles interact with the volcano's plume of electrically charged ash, creating a sort of "dirty thunderstorm." 2
While long elusive, photos of these natural fireworks were captured in 2009 during the Alaskan eruption on April 14, 2009. Ironically, this is the same date that Eyjafjallajokull erupted in Iceland exactly one year later, spewing significant amounts of ash and causing global disruption. A few days later dirty thunderstorms were also observed. A series of images of the volcanic lightning produced from Eyjafjallajokull's activity were published by NBC that year. 3 Iceland is a hotbed of volcanic activity. Experts consistently have their eyes on a number of volcanoes located in the country including Hekla, Tekla, Laki, Bardarbunga and the aforementioned Eyjafjallajökull.
Hekla - July 1993 Gipsyqueen/Creative Commons license-Attribution/Share Alike
A dirty lightning storm is also suspected to have occurred during a volcanic eruption in Chile in 2008. Some experts say it could be this phenomenon occurs more often and just happens so fast it isn't seen or able to be captured in time.
Dirty thunderstorms, while fascinating to watch and, if images are any indicator, a most incredible sight. They are also said to be very dangerous. Being much is still unknown about this amazing volcanic activity there is little doubt science will continue to study this remarkable creation made by Mother Nature, especially as technology develops and more tools and measuring techniques are established
Perhaps one day soon far more will be known about it.
Dirty thunderstorm footage captured earlier in 2015