Reports of “earthquake lights,” like the ones seen in videos captured before Friday’s 6.8-magnitude earthquake in Morocco, go back centuries to ancient Greece.

Reports of “earthquake lights,” like the ones seen in videos captured before Friday’s 6.8-magnitude earthquake in Morocco, go back centuries to ancient Greece.

Earthquake lights can take several different forms, according to a chapter on the phenomenon coauthored by Derr and published in the 2019 edition of the Encyclopedia of Solid Earth Geophysics.

Earthquake lights over Tagish Lake in the Yukon-Alaska border region. The photograph was probably taken in July 1972 or 1973 (exact date unknown). The estimated diameter of the balls is about 1 m ...