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.[1] 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.[2][3][4]