The Ocean Basins
Five Major Oceans
Arctic
Pacific
Atlantic
Indian
Southern
Five Major Oceans
Atlantic – 2nd largest & youngest
ocean (3.3km average depth)
Indian – 3rd largest ocean (3.8km
average depth)
Pacific – 1st largest & deepest
ocean (3.9km average depth)
Five Major Oceans
Arctic – 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
How
SONAR
works…
receiver
ocean surface
transmitter
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 level
Avg 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