I presume they are, but i noticed them first time on 3rd or 4th level, where some hallways are collapsed and I'm just thinking that it would be cool if hallways are collapsed because of the earthquakes and that you could outrun them. And I don't know if earthquakes are time or location triggered.
So for example if earthquakes are time triggered, and you get to the (should be) collapsed hallway and it is not collapsed then you don't have to go all the way around.
Edit: Anybody been there, done that before the first earthquake?
It's hard to prove a negative, but I believe that the earthquakes are only for flavor. I started a second playthrough on easy where I ran to the first collapsed hallway of the game as quickly as possible, and it was still collapsed. I also spent some time on the Legend of Grimrock forums and saw that other people had pretty much the same experience. I haven't seen a credible reported case of "Yeah, I was able to beat the earthquake and get through a tunnel before it collapsed!"
In short, the earthquakes that occur are semi-random in nature and don't seem to be tied to the collapsed hallways.