They are the deepest abysses that presents the seabed and which are formed by the action of plate tectonics. The ocean trenches are narrow and deep trenches that are often found attached to the continental edges or along with bows of volcanic islands, especially in the Pacific. Deep underwater depression.
They are deep and narrow cavities that are often found in the waters of some oceans, particularly in the Pacific. They are next to the edges of volcanic islands or on the sides of the continents. The water temperature is very low ( 0 - 2 ° ) and some measuring more than 11000 meters. Example the Challenger trench or Mariana.
