A strange thing happened around 3-4AM. I was hearing very low sounds that I couldn’t place. I thought I felt them just a little, but mostly I heard them about as low as my hearing goes. I got up, wandered the house- couldn’t make sense of it. The dog was apoplectic, and hiding.

I checked my seismograph, and lo and behold- there WAS something. I checked nearby seismographs to see if it was just at my place, and no- it was regional. I was hearing these seismic thumps. That’s a new one. You can see them in the chart below (from my seismograph, but virtually the same on nearby peers).