Great subject Inja, not sure what forum is best, this one probably jsut as good, but not a lot of traffic in here.
I watched the first part, didn't have time for the entire thing yet. Very starnge sounds that are coming from the bowels of earth. I had something similar happen to us, not exactly they same erree sounds, but massive rumblings. If you recall I live In Northridge, Calif. where the big earthquake hit us in Jan, 1994. We live right on top of the epicenter, which we referred to as Ground zero, and we literally were right on the center of it. We are only 1/2 mile south of CSUN, and the famed collaped apartments, mall, and University, and actually closer as the crow flies to the epicenter. For about 3 months, we were scared to sleep in bedrooms and all slept in the living room right next to the front door. Thousands of aftershocks, dozens considered major quakes in themselves.
What would happen is preceeding any shaking, a horrendous rumble would emit from the ground, followed about 3 seconds later with the house shaking like you would not believe. Probably experienced hundreds of them over several months until you finally got use to it. For weeks, we would hear them, and just rise off you chair to head for the door, and the shaking followed. Those were obviouly the should of earth moving, which was 7 miles deep, and the sound would travel faster than the phyical vibration. The odd thing was this only occured to those right on top of the epicenter, and not those further out in the radius of it. There was major distruction for a 20 mile radius, and it was felt hundreds of miles away, but this sound thing was only felt close in.
These other noises remind me of old houses that develop creaks and odd sounds, that may reach to temperature changes, of plumping noises from vents that result from odd air moving in them. Nothing will casue a bigger noise in a house than a bubble of air in your water line, when you turn off the water to fix something.
One thing I learned about in the rocket business was the harmonics that can develope and vibrations that can develope that are unexplainable. The vibrations set up a force that create a harmonic reaction.
I don't have a clue what casues these noises but the earthquakes made me aware of sounds that can come from way down deep. The earth is a moving combination of plate techtonics, underground rivers and streams, vast pools of oil, temperatures colliding, all putting forces and pressure on each other. Mother Nature working full time, at a slow pace, but something has to move and give with all these forces.
Sound is vibration, and vibration is movement. Throw in some forces like solar flares, gravity and earths magnetic forces, its all pretty mind boggeling to me.
One last point about the earthquake, was the level of the sounds. During the main quake, not just the noise of the house shaking, but the noise emitted by the quake was so loud you could not hear yourself scream and I was, nor did I hear a grandfather clock fall against my head. the noise predeeding aftershocks was as loud as hearing a loud truck right next to you, but not deafening.