Most of the deep-sea floor lies at a depth of 16,500 ft. The deep-sea floor or abyssal plain, rises at a very gentle slope of less than 1 degree toward the mid-ocean ridge.Though relatively flat, it often has submarine channels, low abyssal hills, plateaus, rises, and other features. It is collectively termed as dee-sea basin.

This deep-sea basin is dotted with volcanic islands and submarine volcanoes called seamounts.