Tuesday, March 3, 2015

Volcano Lightning! How?

Thousands of Chileans are being evacuated from their homes as one of South America's most active volcano blows its top. The name of this geologic menace is "Villarrica", and it began its tirade shortly after midnight on Tuesday. The evacuations were issued because authorities feared the oozing lava would melt the snow and ice and cause major flooding. Villarrica is covered by a glacier cap covering some 15 square miles. It is also capped by snow starting at around 5000 feet high.

This volcano rises 9,000 feet and is located near the small city of Pucon, roughly around 400 miles south of  Chile's capital, Santiago.

Yet, the most impressive thing about the eruption, was the lightning sparking from the spewing lava. It is keeping tourists, locals, and emergency managers in awe.

This image, courtesy of the Associated Press, shows the incredible lightning show shooting through the cloud of ash.
But how does this happen?. Well check out this article courtesy Popular Science:

The weird appearance of lightning during volcanic eruptions has been documented for some time now, but until recently, scientists weren't sure what caused the lightning bolts to appear. They were pretty sure it had something to do with the particles of ash from the eruption getting an electric charge as they spewed out of the volcano, but nobody could figure out how the charge got there. And getting a closer look wasn't exactly an option, since directly observing a volcanic eruption isn't the safest thing to do. Ash, lava, lava bombs ... there's a reason that the area around Villarrica was evacuated.

But in 2013, there was a breakthrough. Scientists at Ludwig Maximilian University of Munich managed to create volcanic lightning in a lab, suspending particles of volcanic ash (gathered from sites around the world) in argon gas, then forcing the concoction through a narrow tube and into a tank. The process mimics an eruption, when particles go from a compressed environment under the earth's surface into the atmosphere.

The researchers videotaped their experiments and found that the particles of ash manage to charge each other through friction, just rubbing against each other during the 'eruption'. When the charged particles enter the tank, energy is discharged, creating tiny lightning bolts.
In nature, those tiny lightning bolts can be huge, making for some spectacular photos of eruptions that look an awful lot like a supervillain's lair. But in this case, it's not science fiction, just science friction.

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