Luminous phenomena associated with earthquakes
DefinitionEarthquake lights (EQLs) are anomalous luminosities associated with and presumably caused by the accumulation of stress, most characteristically before or during a seismic event or during an aftershock sequence. There is some disagreement over whether the term "earthquake lights" should also be applied to similar luminous phenomena observed in earthquake-prone areas or along faults without immediately associated seismic activity. In these cases the EQLs may be due to locally high stress levels in the Earth's crust that wax and wane without catastrophic rock failure or by earthquakes which are too distant or late relative to the observed EQL.
Classification of Earthquake LightsThe earliest known report of earthquake lights dates to at least 373 BCE when the Greek cities Helice and Buris were destroyed by an earthquake accompanied by "immense columns of fire" (Seneca). Ancient references will always be