Hedervari supports the hypothesis that some earthquake lights, particularly those preceding strong regional quakes, are caused by the release and ignition of gases from the stressed rocks. Several curious features of earthquake lights favor this assertion:
Prequake lights are regional in character corresponding to the widespread flexing of the strata. (In the 1933 Japanese quake, earthquake lights were seen along a 1000-km arc);
There is no correlation between the earthquake epicenter and the location of earthquake lights. (In the 1977 Romania quake, the epicenter was east of Cluj but the earthquake lights lit up the western horizon.
(Hedervari, Peter; "The Possible Correlations between Crustal Deformations Prior to Earthquakes and Earthquake Lights," Seismological Society of America, Bulletin, 71:371, 1981.)
Comment. In essense, Hedervari is saying that earthquake lights often do not occur where rock stresses are greatest and that the piezoelectric effect may not be the whole story.
Reference. Many examples of earthquake lights are presented in our Catalog: Lightning, Auroras, in category GLD8. To order this book, visit: here.
"Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada>, Vol. 81, no. 1 (1987), p. 24., 02/1987