Link

The authors suggest that, during an earthquake, the stress of rocks grinding against each other generates electric charges, which travel upwards along the nearly vertical geological faults that are common in rift zones. When the charges reach Earth's surface and interact with the atmosphere, they create a glow.

"Earthquake lights are a real phenomenon--they're not UFOs," says lead author Robert Thériault, a geologist at Quebec's Ministry of Natural Resources in Quebec City, Canada. "They can be scientifically explained."

Oh, i got your scientific explanation right here. It's pretty obvious to me that these glows followed by earthquakes are caused by Megalon digging his way out of Seatopia. Der.