The Ocean Basins

Five Major OceansArctic

Pacific IndianAtlantic

Southern

Five Major OceansAtlantic – 2nd largest & youngest ocean (3.3km average depth)

Pacific – 1st largest & deepest ocean (3.9km average depth)

Indian – 3rd largest ocean (3.8km average depth)

Five Major OceansArctic – the smallest & shallowest ocean (1.4 km average depth)

Southern – 4th largest ocean; surrounds Antarctica (3.8km average depth)

What is a sea?

Small area of the ocean that is

partially surrounded by

land

The Seven Seas

Numerous seas – they are all considered part of an ocean

Exploring our Oceans

• Oceanography is the study of the physical characteristics, chemical composition and life forms of the ocean.

What are Submersibles?

•Underwater research vessels

The Alvin

The Jason

SONAR• Important to help map ocean floor•Sound Navigation and Ranging

transmitterreceiver

How SONAR works… ocean

surface

ocean floor

Differences in the time it takes for the sound waves to leave the boat and then return tell scientists how deep the ocean bottom is.

Features of the Ocean Basins•Continental margin: portion of

ocean made up of continental crust

Features of the Ocean Basins• continental shelf: flat part of

continental margin covered by shallow ocean water

Formed by changes in sea levelAvg depth = 60 m

Features of the Ocean Basins•continental slope: boundary

between continental crust and oceanic

Features of the Ocean Basins•submarine canyons: deep, v-

shaped valley that cuts through shelf & slope

Features of the Ocean Basins•continental rise: wedge of

sediments that separates slope from ocean floor

Features of the Ocean Basins•abyssal plain: large flat area on

the ocean floor

Features of the Ocean Basins•seamount: underwater volcanic

mountain (1000m)

Features of the Ocean Basins•guyot: a flat-topped submerged

seamount

Features of the Ocean Basins• trench: deep narrow valleys along

the edges of ocean floor

Marianas Trench in Pacific ocean is 36,000 ft deep (6mi) – deepest

point

Features of the Ocean Basins•mid-ocean ridge: mountain range

on ocean floor

Features of the Ocean Basins• rift valley: deep crevice in between

mountain ranges

Features of the Ocean Basins

•coral reef: limestone structures containing shells of animals that surround volcanic islands