According to the New Madrid, Missouri web site, during the 1811-1812 earthquakes there were reports of lights coming from the ground due to quartz crystals being squeezed. They call this phenomena “seismoluminescence.” There are also videos online taken during the 2017 Chiapas, Mexico earthquake showing strange lights in the sky. Lights have been reported associated with numerous other earthquakes throughout history.
Is there any research that has been done to either prove or disprove that these reported lights are actually being caused by the earthquake, and if so how are the lights created?