"How long before a quake do you think" I don't know, I'm not a geologist, vulcanologist nor any type of earth scientist. Moreover, I reckon it'd be impossible

"How long before a quake do you think" I don't know, I'm not a geologist, vulcanologist nor any type of earth scientist. Moreover, I reckon it'd be impossible to generalize as every instance would be different. The only thing one could say in the absence of data would be that EM effects would build up over time to a tipping point and then quickky release like a sawtooth waveform but if you want more accurate info then ask the experts. The point I was making was that because of stresses on rock forces build up and produce EM waves before the tipping point occurs. It's detecting the build-up before its release that has the potential to save people. I've lost track of those original papers that influenced me. If anyone comes across them I'd like the references.