A flat abyssal plain- is an underwater plain on the deep ocean floor, usually found at depths between 3000 and 6000 m.
An underwater seamount or guyot- A guyot also known as a tablemount, is an isolated underwater volcanic mountain (seamount), with a flat top over 200 metres (660 feet) below the surface of the sea.
A continental shelf, break, slope, and rise- The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods
A submarine canyon on the contential shelf- is a steep-sided valley cut into the sea floor of the continental slope, sometimes extending well onto the continental shelf.
the mid-ocean ridge - are geologically active, with new magma constantly emerging onto the ocean floor and into the crust at and near rifts along the ridge axes.
A trench and island arc- is a type of archipelago, often composed of a chain of volcanoes, with arc-shaped alignment, situated parallel and close to a boundary between two things.