Earthquake light

The phenomenon differs from disruptions to electrical grids – such as arcing power lines – which can produce bright flashes as a result of ground shaking or hazardous weather conditions.

[15] On September 8, 2017, many people reported such sightings in Mexico City after a 8.2 magnitude earthquake with epicenter 740 km (460 mi) away, near Pijijiapan in the state of Chiapas.

[16] Appearances of the earthquake light seem to occur when the quakes have a high magnitude, generally 5 or higher on the Richter scale.

[17] Instances of this phenomenon appear in videos[18] taken seconds after a 7.1 magnitude earthquake in the city of Acapulco, Mexico, around 20:47 on 7 September 2021.

The New York Times reported that "Videos from both Acapulco and Mexico City also showed the night sky lit up with electrical flashes as power lines swayed and buckled.

[20] A 2023 study found the earthquake light coincided with a magnetic disturbance detected by a geomagnetic observatory, and ruled out "the possibility of the flashes being caused by explosions in transformers or power supply facilities" by checking the maintenance reports of regional power stations, none of which had malfunctioned near the location of the observed light.

Social media users including Webcams de México posted videos of blue lights which seemed to be radiating upward.

Once they reach the atmosphere these ions can ionise pockets of air, forming plasma that emits light.

[27] One hypothesis involves intense electric fields created piezoelectrically by tectonic movements of quartz-containing rocks such as granite.

[29] During the American Physical Society's 2014 March meeting, research was provided that gave a possible explanation for the reason why bright lights sometimes appear during an earthquake.

The researcher, Troy Shinbrot of Rutgers University, conducted experiments with different types of grains to mimic the crust of the Earth and emulated the occurrence of earthquakes.

[30][31][32] In 2016, podcaster Brian Dunning said he was skeptical that the phenomenon even existed, citing a lack of direct evidence.