Earth Lights Explained

For thousands of years, human being has marvelled at the strange phenomena called earthlights (sometimes called ghostlights). To Native Americans these peculiar lights (which can appear as flickering flames or balls of light), marked the doorway to different realms. Others have claimed they are of extraterrestrial origin, whilst some folk associate them with ghosts or demons. The lights are certainly strange, and they appear all over the world. Sometimes they appear randomly, at others they may almost have a set routine. They come in a variety of colours, including red, orange, blue, yellow and white; they often seem to bob or bounce along. Until recently, there has been no conclusive answer as to what causes them. However, an analysis of over 65 documented earthlight cases published in the journal Seismological Research Letters this month, may have the answer. It seems the earthlights have appeared occurred during or before several of the world's greatest earthquakes; including two days before the Great San Francisco Earthquake of 1906. Yet, because they were hard to explain, and all the reports were anecdotal, many scientists believed the lights did not exist. The scientists may now be convinced that the lights exist, but they are not entirely sure what causes them.  The researchers studied 65 cases from North and South America and Europe. Of these, 97% seemed to happen at faults within continental plates. This is odd, as most large earthquakes happen at subduction boundaries where one plate is slipping below another. Surprisingly, about 85 percent of the lights happen in areas where the tops of the continental plates buckle; creating rifts, where the Earth pulls apart. The rifts form steep faults that reach deep down into the Earth's magma, allowing magmatic rocks, that were once buried deep below ground, to move nearer to the surface. The authors think that the crystal structure of these magmatic rocks means that when they are stressed, they are more likely to produce electricity; this then flows to the surface, ionizes the air, and produces flashes of light. According to John Derr, a Seismologist at the Albuquerque Seismological Laboratory, the earthquake lights also appeared at other nearly vertical faults, such as the San Andreas fault. He explained that the faults seem to make it easier for electrical charges in the rocks to reach the surface. It seems when it comes to earthlights, scientists have finally truly seen the light.