Expert explains how lightning sparked Glenpool fire

Tuesday, June 13th 2006, 5:42 pm
By: News On 6

Witnesses say a lightning bolt hit somewhere on or near the five million gallon gasoline tank that caught fire near Glenpool and officials say that's what likely caused the explosion.

But the tank was covered and meteorologists say lightning can't just punch a hole through metal.

So what caused the explosion? We talked to one of the world's foremost experts on lightning at the University of Oklahoma.

News on 6 reporter Steve Berg says you probably don't need reminding, but lightning is pretty potent stuff.

The heat in a lightning bolt is between 10,000 and 30,000 degrees Kelvin, five times the temperature of the sun.

In this case though, lightning expert Bill Beasley says what's more likely is not the heat of the lightning, but rather a spark igniting gasoline vapor outside the tank.

The tanks are vented, and while officials say there wasn't much vapor inside these tanks, it doesn't sound like it takes much.

"If there's vapor coming out of a vent somewhere and it strikes nearby, it can set it off," Beasley says. "That's happened in aircraft. Aircraft gasoline tanks and wings, they get struck and blow them off. That used to be C-130's had a problem until they fixed it back in the 50's. There were some planes that were blown out of the sky that way."

There are ways to try to direct a lightning strike away from sensitive areas.

Even with the best measures though, Beasley says lightning can be unpredictable.

"It's pretty much a random matter of exactly where it strikes," says Beasley.

Dr. Beasley says the same danger applies with static electricity when you're filling up your car's gas tank. A spark can set off those vapors too.