Earthquake light

An earthquake light also known as earthquake lightning or earthquake flash is a luminous optical phenomenon that appears in the sky at or near areas of tectonic stress, seismic activity, or volcanic eruptions. There is no broad consensus as to the causes of the phenomenon (or phenomena) involved. 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.