1. White-Hot Show at Iceland Volcano>
Photograph by Peter Vancoillie, Your Shot>
A blast of white-hot lightning crackles over Iceland's EyjafjallajÃ¶kull volcano on Sunday. Clouds of volcanic ash from Eyjafjallajokull have snarled European air traffic for nearly a week.
National Geographic Your Shot submitter Peter Vancoillie took the photograph from about 18 miles (30 kilometers) away from the volcanic lightning storm, which not "unlike a regular old thunderstorm," said Martin Uman, a lightning expert at the University of Florida in Gainesville.
The same ingredients are present: water droplets, ice, and possibly hailâ all interacting with each other and with particles, in this case ash from the eruptions, to cause electrical charging, Uman said.
The volcanic-lightning pictures are 'really very sensational,' Uman said. 'Somebody ought to be up there with an HD movie camera. It's ready for the IMAX theater.'
2. Purple Bolts at Iceland Volcano>
Photograph by Marco Fulle, Barcroft/Fame Pictures>
Italian photographer and scientist Marco Fulle flew at sunset on Sunday over Iceland's erupting Eyjafjallajokull volcano to capture this picture of purple lightning bolts streaking through the sky.
Much of the lightning generated by the Iceland volcano is better termed long sparks, said the University of Florida's Uman. Those may include a new type of lightning recently found over an Alaska volcano.
It's unknown how such sparks form, though one possibility is that electrically charged silica-an ingredient of magma-interacts with the atmosphere when it bursts out of Earth's crust, Steve McNutt of the Alaska Volcano Observatory said in February.
3. Fire, Ice, and Lightning >
Photograph by Rakel Orvar Atli Thorge, NordicPhotos/Getty Images >
Fiery lava mixes with blue ash and golden lightning over the erupting Eyjafjallajokull volcano in an April 18, 2010, picture.The Iceland volcano's lightning is probably creating distinct symphony of sounds, said the University of Florida's Uman. For instance, small sparks of about 30 feet (9 meters) to about 300 yards (91 meters) make sounds like rifle shots, while the miles-long bolts produce the deep, familiar rumbling we associate with thunderstorms, he explained.
4. Stormy Mix at Iceland Volcano >
Photograph by Marco Fulle, Barcroft/Fame Pictures >
Pictured Sunday, lightning at the Eyjafjallajokull volcano branches off in many directions-an interesting phenomenon, according to the University of Florida's Uman.
Every bolt has a direction that it travels, Uman explained: A spark begins in electrically charged spot and then travels either up, down, or sideways until it reaches an oppositely charged area.
5. Lava and Lightning in Iceland >
Photograph by Oli Haukur Myrdal, Your Shot >
Spurts of lava mix with lightning over Iceland's Eyjafjallajokull volcano on Sunday.
National Geographic Your Shot submitter Oli Haukur Myrdal captured the electrifying light show. All types of lightning, particularly volcanic lightning, are still largely mysteries to scientists, University of Florida's Uman said.
Since people can't easily get inside thunder and lightning storms, no one knows exactly how they form, he said. However, scientists can install instruments near volcanoes' vents to measure certain data, such as the lightning-detection devices that scientists are installing right now in Iceland, he said.
6. Flash and Ash at Volcano >
Photograph by Olivier Vandeginste, Your Shot >
Lightning pierces the erupting volcano's ash cloud in a National Geographic Your Shot photograph taken by Olivier Vandeginste on Sunday.
Inhaling the tiny pieces of glassy sand and dust in the cloud can cause irritation of the eyes, nose, and throat, say experts who advise Europeans to stay indoors when the ash begins to fall. Finer particles can also penetrate deep into the lungs and cause breathing problems, particularly among those with respiratory issues like asthma or emphysema.
But if people could witness the volcanic lightning safely, it would be an incredible experience, Uman said.
'Everyone would want to see that,' Uman said. 'It's like going to see aurora borealis near the North Pole-it's a once-in-a-lifetime experience.'
(Courtesy: National Geographic)