What caused the tremor in the movie?

In the special features deleted scene where the captain is talking to Vickers in her living quarters, a tremor occurs where he ask Chance what or where that tremor came from? Does anybody know what is causing the tremor? At first I thought it was the Engineers Juggernaut, but at this point in the movie, Weyland was just waking up, also stated in the scene, so what in the heck caused that tremor????