"Yep.....it was an earthquake. We don't know if the news media has picked up on it yet but ...The "booms” that were reported on Friday morning were, in fact, earthquakes.
We made an inquiry with the Western Observatory @ Boston College that morning. Apparently they were closed for the Thanksgiving weekend but just reported back to us that they did register two earthquakes Thursday morning - the first at 9:05am and then again at 9:42am. Both quakes had the same magnitude of M1.8 and were both very shallow events meaning they were audible events. Small earthquakes at a very shallow depth are commonly heard and reported as sounding like explosions.
We have included a “picture” of the ground motion as recorded by the Western Observatory. I highlighted the seismic waveforms for you, surrounded by white boxes along the 09:00 horizontal (blue) line. Cool stuff."