Arty practice over at the Fort today and the house is rumbling. You can keep that quake business - freaks me out. I'll keep the booms.
I have that too. In spite of the incredible distance, I think I can hear the big helicopters if I put my ear up to my wall. It gets pretty rumbly at times. I've never mapped it out but I'm guessing that the boom boom part of Camp Pendleton is probably 15 miles away from my place as the crow flies.
The reason I think it's helicopters making the low frequency rumbles is because of the frequency and the frequency. The rhythm matches the monster helicopters. There have been nights when I'm trying to sleep and I hear it too.