For those who saw this in the theatre

Indeed they did, the sensurround system took up the entire front row of seats iirc...

I saw this in a theater that shared a wall with a liquor store. They had to remove their bottles from the common wall otherwize they would fall off during the earthquake scenes.

I saw it in an L.A. theater during its first run. In the earthquake scenes, there was a very deep, loud bass rumble from the sound system, synchronized with the seats vibrating. I don't know how they did it. I suppose it was supposed to be scary, but the audience laughed.