A few days ago, a 7.1 magnitude earthquake struck Acapulco in southern Mexico. It killed at least one person. The quake was also felt in Mexico City. Frightened residents took to the streets after hearing the seismic alert. In the sky, large lights accompanied the seismic movement. It’s not the first time it’s happened. What causes the mysterious flashes in the earthquake in Mexico?
Earthquake lights
Researchers at Rutgers University in the United States explain it. They know how the flashes of light are produced. Landslides near the Earth’s geological faults generate an electric charge.
They are known as “earthquake lights.” They have been documented since the 1600s, according to the United States Seismological Association. It happened two days before the 1906 San Francisco earthquake. A couple saw beams of light along the ground. And in the case of Quebec, Canada, in 1988, there is another example. A bright pink and purple globe of light was sighted 11 days before the devastating quake.
In the case of the 2009 L’Aquila, Italy quake, “flames of light” were seen coming out of the cobblestones. It was seconds before the quake. Numerous flashes of light were recorded by security cameras during the 8.0 magnitude earthquake in Pisco, Peru in 2007.
These earthquake lights can occur before or during seismic movements. The most common lightning in the sky is from a buildup of electrical charge in the clouds. But these lights appear because of the great increase of electric charge on the ground. And that happens when the earth breaks up.
Electricity in every movement
The results were presented at the meeting of the American Physical Society. It was done by biomedical engineer Troy Shinbrot. His lab created a miniature model. It replicated the stresses, strains, and ruptures that happen during an earthquake. They filled tanks with different kinds of grains. From flour to fine glass beads, and they shook them intermittently to create cracks. This generated hundreds of volts of electricity. In other words, even subtle slips of the ground can charge the Earth and cause lightning in the sky.
“Not every great earthquake is preceded by lightning. Nor after all lightning strikes in a clear sky are followed by an earthquake,” Shinbrot commented.
“They seem to be the precursors of some large earthquakes, magnitude 5 or greater. But the voltage signal is not always the same. Sometimes it’s high and sometimes it’s low,” he added.
But these light warning signals could help prevent disasters. In the case of the L’Aquila earthquake, they did. One resident saw the flashes inside his house two hours before the quake and moved his family to safety.
The mysterious flashes in the Mexico earthquake are being replicated around the world. Let’s just hope we don’t see them too soon.
