Deep and extremely flat features found on ocean floor they are the most level places on Earth.
The measurement of ocean depths and the charting of the shape or topography of the ocean floor.
In regions where trenches do not exist the steep continental slope merges into a more gradual incline this exists.
Found near the center of most ocean basins and interconnected system of underwater mountains that have developed on newly formed ocean crust.
Includes all animals capable of moving independently of the ocean currents by swimming or other means of propulsion.
Includes all organisms - algae, animals, and bacteria - that drift with the ocean currents.
The layer of ocean water between about 300 meters and 1000 meters where there is a rapid change of density with depth.
The layer of ocean water between about 300 meters and 1000 meters, where there is a rapid change of temperature with depth.