1) An earthquake at the sea bed 2) Cause of a tidal wave 3) Deep shaking 4) Earthquake 5) Ocean event 6) One might shake the bed 7) Quake 8) Salt shaker 9) Seism 10) Source of some big waves 11) Sub shaker 12) Submarine earthquake 13) Temblor 14) Tsunami cause 
• (n.) A quaking of the sea.
(from the article `earthquake`) ...mile) per second, the speed of sound in water. If such waves meet a ship with sufficient intensity, they give the impression that the ship has ...
Sea'quake` (sē'kwāk`) noun A quaking of the sea. 
[n] - an earthquake at the sea bed
submarine earthquake noun an earthquake at the sea bed