A very rare occurrence before and during earthquakes are lights being seen. Such phenomenon is called earthquake lights or earthquake lightning. These iridescent wonders have been noticed since ancient times and have been visible anywhere from just a few seconds, to as early as 11 days before.
A faint rainbow of lights were reported 2 days before the San Francisco, California earthquake that struck on April 18, 1906. On other times, earthquake lightning has been observed when the quake has actually commenced, or for a short time afterward.
These fiery glows resemble an aurora, also called a polar light; the natural light display produced by ionized electrons from solar winds and magnet sphere plasma stimulated by atmospheric components as seen in the high latitude (Arctic and Antarctica regions).
Colors of earthquake lights are white to a bluish hue, but other colors have been seen, as purple pink floating globes. Earthquake luminosity may also appear as sizzling flames emanating from green shimmers. In other cases, yellow ball shaped lights appeared before earthquakes.
https://www.youtube.com/watch?v=9ZPm97HABL8
Appearances of earthquake lights seem to occur when the quakes have a high magnitude, generally 5 or higher on the Richter Scale. When observed, the luminosity is reported to be visible for several seconds, but last for tens of minutes.
Estimates of distance of the lights from the epicenter of an earthquake vary; as in one case, lights were reported 70 miles (110 km) from the epicenter, as in the case of the 1930 Idu Peninsular earthquake in Japan. In another case, lights were spotted in Tianshui Gansu only 400 kilometers of the 2008 Sichuan mainland China earthquake’s epicenter.
Earthquake lights have been often mistaken for UFOS or even angry spirits of the dead that soon afterwards caused seismic tremors.
In the 1970’s, Jim Conacher, a retired Canadian agriculture inspector, took a photograph of seven yellow luminous spheres he had seen floating on a mountain on the Tagish Lake in the Yukon territory of Canada. Mr. Conacher thought he was seeing UFOs. The photograph of the strange lights became massively circulated on social media recently as a visible collaboration of an encounter with UFOs.
Friedeman Freud, carefully studied the photograph, as well as his team of researchers. Freud is an adjunct Professor of Physics at San Jose State University and a senior scientist at NASA’s Ames Research Center. He and his team discovered the timing of the photograph by Conacher seemed to place it just a few hours before the Cross Sound earthquake of July 1, 1973 which measured 6.7 on the Richter Scale. Those lights are now believed to be earthquake lights.
Some people have mistaken earthquake lights for other phenomena, as well, as ball lightning, meteors, iridescent clouds, light pillars, circumhorizontal arcs(fire rainbows) or sundogs.
Professor Freund and his colleagues believe what causes earthquake lights is based on seismic waves hitting rocks as basalts and gabbros, that have tiny defects on their crystals. The process causes electrical discharges that form as plasma which build up in the rocks and then bursts out on to the surface to make a colorful display of electrical discharges in the ionized air.
Another theory by other scientists is that earthquake tremors stimulate quartz bearing rocks to rub together, producing electricity from the piezoelectric effect that also disturbs the magnetic field of the earth through tectonic stress.
Both conditions are believed to occur only under rare instances involving earthquake activity.
