So the ship gradually fills with water, going down steadily by the bow.
Finally, the stern starts to tip upwards. Then the stern breaks off, and the two pieces of Titanic sink beneath the water.
So how long from the moment the ship disappears beneath the water until it hits the ocean floor?
And, suppose such an accident were to happen today: would the impact of the pieces of Titanic on the ocean floor be enough to show up on modern seismographs?