Ocean Floor Features

Beth Roland

Eighth Grade Science

Regions of the Ocean Floor

• 2 Major Regions– Continental Margin – consists of the

continental crust (shallow end of the pool!)• Continental shelf- begins at the shore line and

slopes gently to the open ocean. (surface to a depth of 200 m)

• Continental slope- steep slope that begins with the continental shelf and ends at the ocean floor (200 m – 4,000m)

• Continental rise-base of the continental slope. Consists of piles of sediment.

Regions of the Ocean Floor• Deep-ocean basin is made of the oceanic

crust (deep end of the pool!)– Abyssal plain- broadest and flattest section of

the deep ocean basin. Home to many unique life forms which are adapted to survival in its cold, high pressure, and dark conditions

– Mid-ocean ridges- underwater mountain chains formed where tectonic plates pull apart from one another.

• Pulling creates cracks or rift zones. Magma will fill open spaces causing the sides to expand and create ridges

Regions of the Ocean Floor

– Rift Valley-forms between the ridges of mountains.

– Ocean Trenches- Huge cracks in the deep ocean basin that form when one oceanic plate is pushed beneath a continental or other oceanic plate.

– Seamounts- individual mountains made of volcanic material that are formed where magma pushes through tectonic plates. Can build up above land and would become a volcanic island.

Continental Margin and Deep Ocean Basin

Mid-ocean Ridge

Bathymetric Profile