No. 74: Mar-Apr 1991
Numerous earthquake lights (EQLs) were reported between November 1, 1988, and January 2l, 1989, in the Saguenay region of Quebec. These luminosities were associated with 54 seismic shocks recorded in this area. Most were small, but a strong foreshock (magnitude 4.8) occurred on November 23; the main quake (magnitude 6.5) hit 60 hours later. Through appeals by radio and newspapers, 52 observers of EQLs were located. They reported a wide spectrum of luminosities, some of which were very strange. In the sky, some observed silent sparkings, diffuse glows, and aurora-like stripes. For an account of the more enigmatic EQLs, we quote M. Ouellet:
"Fireballs a few metres in diameter often popped out of the ground in a repetitive manner at distances of up to only a few metres away from the observers. Others were seen several hundred metres up in the sky, stationary or moving. Some observers described dripping luminescent droplets, rapidly disappearing a few metres under the stationary fireballs. Only two fire-tongues on the ground were reported, one on snow and the other on a paved parking space without any apparent surface fissure. The colours most often identified were orange, yellow, white and green. Some luminosities lasted up to 12 min."
(Ouellet, Marcel; "Earthquake Lights and Seismicity," Nature, 348:492, 1990.)
Reference. Many observations of earthquake lights are cataloged in GLD8 in the catalog: Lightning, Auroras. For ordering information, see: here.