The Mysterious “Earthquake Lights”
By James Donahue
We
read a lot about earthquakes that are shaking things up all over our world. We read about the threat of tsunamis when the
big quakes occur along coastal areas, and there are the stories about the horrors of the destruction and deaths the major
quakes leave behind. But few talk about the strange flashes of lightning that often occur before, during and just after “the
big one.”
The lightning flashes overhead
has added to the terror experienced by people caught in the extremes of a moving shifting earth under their feet and the danger
of collapsing buildings.
Dubbed “earthquake
lights,” the odd flashes of light that streak through the sky, sometimes in various colors, have been noticed for years
and even photographed. But it wasn’t until recently that scientists have developed theories as to their cause.
The possible explanations have ranged from heat caused by friction,
radon gas or piezoelectricity. The latter is an electric charge created in quartz rocks as the tectonic plates grind together
deep in the earth.
A team of scientists
led by physicist Troy Shinbrot at Rutgers University in New Jersey, studied plastic disks, glass particles and organic powders
like flour that can slip in the same way the earth does during an earthquake. They found that all of the materials they studied
developed an electrical voltage when disturbed.
In
a story that recently appeared in Live Science, Shinbrot noted that unexplained flashes of light occur when various other
materials like transparent tape is peeled from a roll, when wintergreen hard candies are broken in a dark room, or when mercury
slides across glass.
“If you take
a Tupperware contained filled with flour and tip the container, when the flour shifts, voltages of around 100 volts inexplicably
appear,” Shinbrot said.
Thus the
university team suggests that earthquake lights are originating from a buildup of electrical charge in the ground surrounding
geological faults that are in motion. The flashing light show occurs at rifts where pieces of the Earth are pulling apart.
