(NaturalNews) When a magnitude 6.0 earthquake struck Napa Valley, California, on Sunday, August 24, residents from the area noticed strange flashes of light appearing in the sky. The local KPIX 5 newsroom was flooded with calls about a strange phenomenon of lights taking place in the sky. Some people thought the strange lights were UFO-generated, while the more practical ones thought that a transformer exploded in the distance. Some took to twitter to voice their bewilderment: "Everybody felt the earthquake but I'm the only one who saw the blue flashes in the sky??" said one Napa Valley resident. Another person tweeted, "Saw flashes of light that looked like lightning right after earthquake, then huge green flash north of Sebastopol."

Nope, they aren't UFOs, says leading scientist

According to scientist Friedemann Freund, who works at the SETI Institute in Mountain View, the "earthquake lights" are not from UFOs or explosions. They are naturally occurring phenomenons that take place when stress builds up below the earth's surface. The stress of the earthquake on rocks underneath the ground causes an electric current to blast its way to the surface of Earth, shooting into the sky as a burst of colorful light. The earthquake lights seen in Napa Valley were reportedly visible in bursts, with one or two seconds between each flash. The lights were like reverse lightning, shooting from the ground.

Freund says that these lights aren't so rare and they have been reported from earthquakes around the world, from Japan to Peru. His research team had been conducting ongoing research for the past 12 years, investigating at least 65 historic occurrences of "earthquake lights," why they form and how they form, including different varieties of lights.

"When nature stresses certain rocks, electric charges are activated, as if you switched on a battery in the Earth's crust," he said.

Three historic examples include the 1988 quake along the St. Lawrence River in Quebec. Eleven days prior to the quake, residents in the area reported a bright purple pink globe of light emanating from just above the ground.

In 1906, the people of San Francisco, California, documented faint rainbows of light appearing just before a major quake struck the region.

In L'Aquila, Italy, in 2009, four-inch flames of light appeared to be bursting above the street just seconds before the earthquake hit.

The energy of rocks within the earth bursting into orbs of light

Quoting Freund, National Geographic reported, "The lights can take 'many different shapes, forms, and colors.'"

In a new scientific paper, he and his research team wrote that certain rocks in specific settings have special electrical properties that are activated under extreme stress, like earthquake activity. Does this prove that something as docile as rocks have a level of energy contained within them? Could this energy be extracted, transferred and used?

Freund says the earthquake lights take on many forms. Bluish flames have been seen coming out of the ground. Orbs of light referred to as "ball lightning" have been seen floating in the air for up to a minute at a time. Some of the more common flashes of light resemble regular lightning strikes and happen in one to two second intervals, spanning 650 feet from the ground.

Intrigued by his own research, Freund said, "There are things that we still don't understand about the earth, so why not accept unusual, exceptionally unusual phenomena taking place? And the light outburst from the ground is one of them."

Sources for this article include:

http://sanfrancisco.cbslocal.com

http://news.nationalgeographic.com