______ are gently sloping areas of the ocean basins

The correct answer is Deep sea plains.

• Deep-sea plains are gently sloping areas of the ocean basins.

Additional Information

• Ocean Floor Division can be divided into various parts such as Continental Shelf, Continental Slope, Continental Rise or Foot, Deep Ocean basins, Abyssal plains or Deep Sea plain, Oceanic Trenches, Seamounts, and Guyots.
  • Deep-Sea Plain or Abyssal plain
    • These plains are gently sloping areas of the ocean basins.
    • These are the flattest and smoothest regions of the world.
    • It is an underwater plain on the deep ocean floor, usually found at depths between 3,000 and 6,000m.
    • These plains are covered with fine-grained sediments like clay and silt.
    • Lying generally between the foot of a continental rise and a mid-ocean ridge, abyssal plains cover more than 50% of the Earth’s surface.
  • Oceanic Deeps or Trenches
    • These areas are the deepest parts of the oceans.
    • The trenches are relatively steep-sided, narrow basins.
    • They are some 3-5 km deeper than the surrounding ocean floor.
    • They occur at the bases of continental slopes and along island arcs and are associated with active volcanoes and strong earthquakes.
  • Continental Shelf
    • The continental shelf is the extended margin of each continent occupied by relatively shallow seas and gulfs.
    • It is the shallowest part of the ocean showing an average gradient of 1° or even less.
    • The shelf typically ends at a very steep slope, called the shelf break.
  • Continental Slope
    • The continental slope connects the continental shelf and the ocean basins.
    • It begins where the bottom of the continental shelf sharply drops off into a steep slope.
    • The gradient of the slope region varies between 2-5°.
    • The depth of the slope region varies between 200 and 3,000 m.
    • The slope boundary indicates the end of the continents.