Hi Glen. I think you might find this interesting.

Something that bothers is the use of granite when a test is being done. Is it only granite that is sufficiently hard enough to withstand movement long enough to generate a major quake, or might there be other rock material that could do the same thing? Take Care…Don in creepy town

“St.-Laurent [6] critically evaluated numerous reports of EQLs associated with the M=6.5 25 Nov. 1988 Saguenay earthquake Québec, Canada, that occurred at 18:46 local time. The reports confirm the diversity of the observed phenomena. One report that seems to be well supported allows us to derive insight into the processes that seem to have taken place around the 29 km deep hypocenter of this earthquake.”

“M. Dallaire, a trapper who is very familiar with the local surroundings, reported that he had just left the wood and was stopped in his tracks by a crackling noise in the trees behind him. The noise was followed by a curtain of bright light that sped past him, over the open field toward and beyond his house ~700 m away as depicted in Figure 1. The curtain of light took ~2 sec to cross the distance of ~700 m. An instant later M. Dallaire felt the arrival of the first P-wave, followed by the S waves.”

“The description contains important details. (i) The event started with the crackling noise that appears to have been caused by electric discharges off the tree branches indicating the buildup of a local electric field. (ii) The luminous curtain suggests an even stronger electric field leading to pervasive discharges at the ground/air interface. The curtain traveled from the epicenter, which is 19 km to the left of the location shown in
Figure 1. (iii) The speed of propagation was in the order of 100-300 m/sec.”

http://elfrad.com/FranceStLaurent_IWSE_2005.pdf

• "P" Hole