Sounding the Sea; A Study in Bathymetric Mapping

Abyssal plain is an underwater plain on the ocean floor, usually found at depths between 3000 and 6000 m.Generally between the foot of a continental rise and a mid-ocean ridge, cover more than 50% of the Earth’s surface. Its among the flattest, east explored regions on earth. 



Guyot  flat-topped seamount, found chiefly in the Pacific Ocean

continental shelf, break, slope, and rise Continental shelf, which is an underwater extension of the coastal plain. The continental shelves are the regions of the oceans best known and the most exploited commercially.The continental slopes begin at the shelf break and plunge downward to the great depths of the ocean basin proper.

A submarine canyon is a steep-sided valley cut into the sea floor of the continental slope, sometimes extending well onto the continental shelf. Some submarine canyons are found as extensions to large rivers; however most of them have no such association.

A mid-ocean ridge is a general term for an underwater mountain system that consists of various mountain ranges (chains), typically having a valley known as a rift running along its spine, formed by plate tectonics
   

An 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 converging tectonic plates.

The ocean floor is measured and mapped by using a technique called Topography. The dictionary definition for Topography is- the detailed mapping or charting of the features of a relatively small area, district, or locality.
It measures the height and shape of a certain area.