Thanks. I believe I read that review while learning about the phenomena.
I first read about it in Jim Smith’s Get Better Sound. We have earthquakes every few months that are clearly felt. ~200 mile radius <mag 5.
https://www.quora.com/Seismology-What-is-the-frequency-in-Hz-of-an-earthquakes-p-wave
I have a couple nice, old wood boxes. Perfect to house a small transducer. And 12V linear wall wart supplies. The board has everything else on it. This one has an LED disconnect too. No reason to run that circuit once you know it’s got power.
I need to learn how much energy we typically receive and how much was it before the industrial revolution.